Tech report blog

WOODLANDS AND LANDSCAPE ARCHITECTS’ RELATIONSHIP WITH ARBORICULTURE

What is a natural woodland?

According to the Forestry Commission: A minimum area of 0.5ha with a minimum width of 20m, a potential tree canopy cover of at least 20%, and a canopy consisting of specimens that meet the definition of trees.

In the 1600s, the ship-building industry grew, and as trees were cut to use, woodlands were turned into agricultural land.

In the 1970s, forestation of the UK was at about 8%, but in 2021 it reached 13%.

Uses of woodlands:

·      Ecology

·      Recreation

·      Timber production

·      Heat absorption

·      Flood amelioration

·      Soil stabilisation

·      Pollution interception

·      Offender rehabilitation

·      Rainfall dissipation

·      Carbon sequestration

Woodland husbandry: making them neat/tidy

Woodland management: list of objectives thinking ahead – which trees will grow together and decades into the future?

Rewilding: nature doing the work for you – a way of introducing ecology

Enlarge scale restoration of ecosystems to the point where nature can take care of itself.  It re-establish his natural processes and other allows them to lead the way, free from set outcomes and fixed and points.

Steps for rewilding:

1.        Don’t do anything until you have a plan

2.        Learn all you can about the site status

3.        Seek advice: expert, local, and internet

4.        Take stock of the locality vegetation, water courses, topography, and features

5.        Formulate a plan – actions, contacts, resources, labour and time scale

6.        Be aware of the ways in which nature works

7.        Apply natural methods and courses of action

8.        Careful species choice: soil location, wildlife encouragement, and compatibility

9.        Be positive and seek to turn difficulties and the unexpected to advantage

10.  Keep good records of events, contacts, growth successes, and failures

11.  Collaboration: mutual benefit of others experience

12.  Communication: keep everyone informed, encouraging local interest and support, and liaise with local wildlife groups

Things to look out for in woodlands:

·      Epicormic growth – side shoots

·      Bad tree form – lower branches die

·      Woodland canopy – closure of crowns

·      Beetle disease: all trees have to be cut within 400 m of infection

Things to consider

·      Forward planning – allow for tree death

·      Course needs to allow for weed management

·      Lower planting encourages biodiversity

Facilities that encourage people to use woodlands: toilets, parking, tea huts, etc.

Other than a few remnants of the Caledonian Pine Forests, we have no natural woodlands in the UK.

GARDEN VISIT – RHS WISLEY, WOKING

Spans 240 acres, made up of formal and informal gardens, glasshouses, and an Arboretum.

Established in 1878 by George Ferguson Wilson (Victorian businessman) it became part of the RHS in 1903 by donation from Sir Thomas Hanbury.  It is now a living laboratory for plant science and education.

In 2024, Pete Oudolf reimagined the glasshouse borders with over 36,000 plants arranged in naturalistic swirls, enhancing biodiversity and seasonal interest

Highlight features at the gardens:

·      The Oudolf landscape – formed by rivers of foliage and flowers.  In autumn and winter, seed heads provide interest for visitors and food for wildlife.

·      Wisteria walk – created in 2018, this walkway flowers in May with two cultivars of wisteria (wisteria floribunda ‘kokuryu’ and ‘kimono’)

·      The orchid house – opened in 2023 house is over 3,000 orchids that have been collected since the 1980s.

·      The old laboratory – this showcases the scientific and exploratory aspect of Wisley with exhibitions of archives and contemporary sources

·      Bowes-Lyon Rose Garden – disco contained a variety of roses in all shapes, sizes, colours, and fragrances (best to visit in summer)

·      Exotic garden – tropic clean inspired, this holds a jungle like atmosphere with exotic plants such as bananas, cannas, and palms

·      Glasshouse – a cathedral like glasshouse with three zones: tropical, moist temperate, and dry temperate

·      Clear lake – a man-made like collecting rainwater for irrigating the garden with gently sloped sides (perfect for wildlife habitats).  This feature is part of the RHS sustainability strategy to be towards neutral by 2030

PLANT PRODUCTION AND SOIL

Tree root system:

Fibrous soil tenure

Tensile guy ropes

Support weight and bending

Arboriculture = justification

The pursuit of estimation

TDAG maxim: the right tree in the right place

TDAG.org.uk

Kew Gardens

Tree selection guide

British standard

BS5837: 2012

Tree protection

RPA: root protection area

Soil provides nutrients, water and anchorage

CO2 +H2O (+sunlight) = C6H12O6 + O2

The urban tree: tree planting and establishment

Characteristics of soil

Soil, particles, particle size distribution and texture

Soil structure and organic matter

Air, water, and exchange of gases

Chemical composition

Comparison of agricultural and urban land

Contamination

Practical soil texture and volume

Compacted soil = no air gaps and water cannot penetrate

Friable soil = airy

PIE CHART

Clay

Expands when wet contracts when dry, which leads to cracking

Sand

Drains very well

Used in golf courses because they are constantly irrigated

Less dense than clay soil

Simple field test

Strata = layers of soil

Soil bulk density = mass of soil (g) / soil volume

Compaction test

California bearing ratio (CBR)

Ability of a surface to support a weight.  Should be a minimum of 5%.

If CBR is too low, cut out imported fill material and build it up again.  Then test.

Protecting soil

No machinery

pH

Measures acidity or alkalinity

6.5 to 7 pH = normal soil

BSI standard publication = specification for topsoil

Contamination:

Soil is passed through a soil hospital, which washes the soil.

“clean” soil that comes out is still contaminated

SOIL PRACTICAL SESSION

GROUND CONTAMINATION

What is contaminated land?

Potentially harmful substances in soil water and ground gas or vapour

Large areas of previously developed land (brownfield)

Controls on waste and use of hazardous materials were limited until the late 20th century, with little consideration for impacts on environment and health

Regulations

Environmental protection act (1990) Part 2A

Town & Country planning act (1990) Planning and development control

Cost of contamination:

£20-£500 per m3 for disposal

£50,000-£1.5m per hectare for remediation

Sustainable development goals

1.    No poverty

2.    Zero hunger

3.    Good health and well-being

4.    Quality education

5.    Gender equality

6.    Clean water in sanitation

7.    Affordable and clean energy

8.    Decent work and economic growth

9.    Industry, innovation, and infrastructure

10.  Reduced inequalities

11.  Sustainable cities and communities

12.  Responsible consumption and production

13.  Climate action

14.  Life below water

15.  Life on land

16.  Peace, justice, and strong institutions

17.  Partnerships for the goals

Sustainability

Bringing Brownfield land back into use is a sustainable practice

Process

1.        Preliminary risk assessment - looking for metallic contaminants, organic hydrocarbon contaminants or asbestos.

2.        Generic quantitative risk assessment

3.        Detailed quantitative risk assessment

4.        Identification of feasible remediation options

5.        Detailed evaluation of options

6.        Development of the remediation strategy

7.        Preparation of the implementation plan

8.        Design implementation and verification of the works

9.        Long-term monitoring and maintenance

Considerations when planning for remediation:

Contaminant type and concentration

Soil type

Remediation objectives

Timeframe, cost, sustainability

WALK AND TALK, KING'S CROSS

These are some of the pictures I took on the site.

HARD MATERIALS

Steintec

High-performance paving, mortars and aggregates to BS7533

Bound and unbound construction

SuDS permeable and non-permeable materials

Sustainability:

Able to be maintained at a certain rate or level

Long-term environmental goal

Sustainable development

Processes and pathways towards sustainability

CO2 – value for carbon emissions making no account for any other greenhouse gases

CO2e – measurement of the total CO2 and greenhouse gases omitted

Carbon index – generic figures for different materials

RIBA – plan of work

0 – strategic definition:

Project scape and feasibility

Produce vision with client

1 – preparation and brief:

Appraisal of spatial require requirements

Identify desired outcomes

2 – concept design:

Architectural concept

Strategic engineering needs

Outline plan

3 – spatial coordination

Masterplan, including spatial arrangements, character areas and material pallette

4 – technical design

Detailed technical specification

5 – manufacture and construction

Logistics, inspection, maintenance manual

6 – handover

Review and evaluation

Green overlay for sustainability

Responsibly sourced materials

Construction and environmental costs

Longevity is key

Lowest bed usually wins…

British standards – download it!

John Ruskin common law of business balance:

Value is in the eye of the beholder

It is unwise to pay too much, but it is also unwise to pay too little

EPD: environmental product declaration

History of pavement design

Rome

Natural stone paving

Granite setts

Cobbles, slabs, setts

Arches are strong

Form must follow function

80s/90s

Sawn granite/ materials

Things to consider:

·      Cement holds it together

·      Maintenance must be considered

·      Evolution of design

·      Failure causes

·      Modern pavement design

·      Unbound construction

·      Bound construction

·      Design considerations

·      Engineering principles

·      Moisture and paving

·      Detailed design

·      Form and function

STRUCTURES AND CIVILS

What is a structure?

Load carrying part of all natural and man-made forms – the part that enables them to stand under their own weight.

Fundamentals of structural engineering

Transferring of loads safely down into the ground via means of structure

Historic examples

Pyramids

Colosseum

Pantheon

Saint Pauls Cathedral

Failures of concrete

Regulations have been made in certain countries due to the failures of early reinforced concrete.

Classification of loads

Dead load = self weight (the frame of the building floors slabs and columns.  This includes finishes and cladding..

Imposed load = user allowed (people in the room, furniture, and movable elements).  This includes wind or snow load.

Thermal load – (due to temperature change). Shrinkage or expansion of materials subject to extreme temperature.

Dynamic load – increased foot fall on a bridge or dancing and jump jumping in arena structures.  This also includes earthquakes.

Materials

Cast iron: 1800 to 1900 – drain pipes, structural framing, aesthetic features

Steel: 1900 to present – structural framing, trusses

Concrete: 1800 to present – framing material, retaining walls, foundations

Masonry/stone: 1800 to present – wall panels, clay pipes

Timber: 1700 to present – trusses, rafters, beams, wall panels

Sustainability

Steel, timber, and masonry can be recycled or reused within another building and if source locally can reduce carbon footprint from the supply chain.

Concrete is less likely to be re-used, but a reduction in carbon footprint can be made in the manufacturing process.

Hierarchy of net zero design

Use less stuff

Specify low impact

Offset

Or…

Build nothing

Build less

Build clever

Build efficiently

Minimise waste

EMBODIED CARBON

This lecture has been extremely interesting and useful as I am focusing my dissertation on coastal wetlands in carbon sequestration and habitat creation.

Lifecycle Environmental impacts

1.        Extraction

2.        Manufacture

3.        Transportation

4.        Installation

5.        Use

6.        Maintenance

7.        Demolition

8.        Recycle/re-purpose

In: Water, materials, and energy

Out: Waste, CO2, and pollutants

Things to consider

Climate change

Water extraction

Mineral extraction

Ozone depletion

Toxicity to humans

Ecotoxicity – freshwater

Radioactive waste

New development/redevelopment

·      Environmental performance and comfort of existing buildings upgraded to avoid the need to demolish and re-build.

·      New buildings designed to minimize energy used to heat and power them.

·      Homes built from materials that minimize the energy and associated CO2e emissions, resulting from their manufacture.

·      Communities designed to encourage walking, cycling and the use of public transport.

·      Communities designed to reduce water pollution, minimize risks associated with flooding and maximising benefits for wildlife and recreation.

·      Parks and open spaces designed and maintained to maximise amenity and health & well-being benefits.

·      New habitats created and existing habitats protected and enhanced.

·      Communities designed with extensive green infrastructure to support urban cooling

Climate change targets and action

·      Heat being trapped in the atmosphere because of the accumulation of greenhouse gases.

·      Temperatures heading up since the start of the industrial era.

·      Hit 1.5 degrees tipping point

·      10-year average estimated to hit 1.5 degree change from 1850 by 2029

·      Coastal flooding and other implications with sea ice melting

UNFCCC

United Nations Framework Convention on climate change 1992

International forum for gaining agreement on tackling climate change.

Kyoto Protocol 1997 – committed industrialised countries and economies in transition to limit greenhouse gas (GHG) emissions.

192 countries signed

Focuses

Adapting to climate change

Mitigation of greenhouse gases

Finance to enable actions

Technology development and transfer

Adapting to impacts of climate change

·      Resistance – increase the capacity of an ecosystem, structure or function to remain relatively unchanged during a disturbance

·      Resilience – Increase the capacity of an ecosystem, structure or function to return to its former state following a disturbance

·      Transformation – allowing or facilitating an ecosystem, structure, or function to transition to new conditions.

·      Reduce GHG emissions, burn less fossil fuels, eat less meat

·      Carbon sequestration – carbon capture and storage, biological sequestration

COP21Paris (October 2015)

Convention of Parties

Paris Agreement – legally binding international treaty on climate change

Goal to hold the increase in the global average temperature to well below 2 degrees above pre-industrial levels and pursue efforts to limit the temperature increase to 1.5 degrees above pre-industrial levels

National Determined Contributions (NDCs) and Ratchet mechanism – countries submit NDCs every 5 years outlining intended emission reductions – these are assessed to determine impact of global temp rise

UK net zero targets

2003: Commitment to reduce CO2 emissions by at least 60% below 199 levels by 2050

2008: Commitment to reduce GHG emissions by at least 80% below 1990 levels by 2050

2019: Commitment to reach net zero GHG emissions by 2050

GHG emissions hd reduced by 50% from 1990 levels in 2022

Full decarbonisation of power systems by 2035.

End sales of new petrol and diesel cars and vans from 2030.

Carbon footprint

Measures the total greenhouse gas emissions caused directly and indirectly by a person, organisation, event or product.

CO2e = CO2 with other greenhouse gases

1 methane molecule = global warming potential of 21 CO2 molecules

STONE

This presentation was very helpful, as I tend to struggle with identifying and choosing stone types for my design.  This will be particularly useful when it comes to the material palette and detailing in my tech report.

Why natural stone?

·      Aesthetically more appealing than concrete or macadam (for example)

·      Offers personality, character and individuality

·      More durable than other stone types – it will last longer

·      Higher quality feel than other stone materials

·      Less embodied carbon

·      Adaptable – consistency with the same stone for various elements (perhaps with different finishes) provides harmony within the design

Considerations for selection

·      Colour – some stones vary in colour, different finishes can provide different colours within a stone, some stone will change colour when wet (in the rain or with water features)

·      Stone type

·      Suitability (e.g. durability for specific use such as steps, paving, or vehicular use)

·      Surroundings and context

·      Planning constraints and guidelines (e.g. only local stone/previously used stone can be used in some conservation areas and areas with particular historic significance may favour a particular type of stone over others)

·      Compatibility – New interventions should be in keeping with existing materials or scheme, and some stone combinations will not always work together.

·      Accessibility and conservation: If original materials cannot be sourced to match with existing materials, preferred alternatives must be compatible/in-keeping with the existing scheme.

·      Cost – Does the desired stone type fit within the budget? Is a lower cost preferred to a higher quality material/aesthetic?

Main stone types:

YORKSTONE (type of sandstone)

·      High strength, low water absorption (less porous and more resistant to staining, frost damage and weather) and high slip-resistance

·      Most are two-toned in colour

SANDSTONE

·      E.g. Caithness from Scotland (black sandstone), Pennant from South Wales and Forrest of Dean stone.

·      Other sandstones tend to be imported

LIMESTONE

·      Difficult to specify

·      Tends to polish under trafficking, so needs texturing to be safe in wet conditions.

GRANITE

·      Comes in a variety of colours

·      Generally hard-wearing

·      Good for kerbs and sets, as can deal with impact loading

·      Aesthetically pleasing in a polished finish for planters and benches, but needs to be textured for pedestrian and traffic circulation

·      Traditionally imported from Europe, but Chinese and Indian granites offer a cost effective alternative

·      Strength: 8-21Mpa

·      Knitted together crystalline structure makes it good at absorbing impact

PORPHYRY

·      Mainly used for paving and setts

·      Warm, multicoloured stone

·      Very strong and durable

·      Difficult to stain

·      Can be sawn and textured

BASALT

·      High strength

·      Limited in sizes

QUARTZITE

·      Aesthetically pleasing with a natural sparkle

·      Comes in a variety of colours such as black, white and green

·      Difficult to quarry

·      Generally only economically viable in smaller plans

SLATE

·      Can be locally sourced (Britain)

·      Very strong and durable

Selection process:

Small samples (coaster sized), Photography, stone consultant, inspecting previous buildings, range samples (blemishes/colour banding can appear in stone, so larger samples should be observed), quarry visit, block inspections and assessments, CE mark & DOP assessment, initial testing, selecting and marking your own block, visit to processing works, sample panel, ethical assessments, full testing, in-supply testing regime, BSEN level for Paving, Setts and Kerbs is set at attestation level 4.

Considerations according to the design/designated space

How is the area going to be used?

Loading and frequency

Ground conditions (better ground allows shallower construction)

CBR should be more than 5%

Surface finishes

·      Textured

·      Sanded

·      Bush hammered

·      Honed

·      Flame finish

·      Sand blasted

Tests to carry out

Every 2 years:

·      Density

·      Porosity

·      Water absorption

·      Flexural strength

·      Compressive strength

Every 10 years:

·      Freeze thaw

·      Abrasion

·      Slip resistance

·      Petrographic analysis

Accreditations

·      ISO9001, Quality assurance

·      ISO14001 Environmental assurance

·      HSE18001 Health & safety assurance

·      BES6001 Responsible sourcing certificate.

Sustainability

·      Carbon reduction

·      EPDs (Environmental product declarations

·      Ethical sourcing

Environmental assessment methods

·      BREAAM: BRE’s Environmental Assessment Methodology

·      LEED: Leadership in Energy and Environmental Design

EPD: A Document that communicates environmental performance or impact of material over its lifetime

·      Compares impacts of different materials on carbon emissions

·      Valid for 5 years

Processes that produce carbon emissions

·      Raw material extraction

·      Transport to factory

·      Storage

·      Transport within the factory

·      Rectification and sawing of blocks

·      Surface finishing

·      Cutting of plates

·      Machining/detailing slabs

·      Packaging and storage

·      Transport to distributor or site

·      On-site application

BRICKS

What is a brick?

A perfect natural blend of earth (clay)

Geological influence:

Clay is formed naturally over many years

Clay bricks:

Highly durable and frost resistant

At the thermal mass of a building

Cost-effective

Non-combustible

Brick manufacture and sustainability:

Claim manufacturing is quarried, water is used, heat recuperation, bricks require minimal plastic to transport, clay brick is self-finishing

Standard brick shapes:

·      Solid

·      Cellular

·      Perforated

·      Frogged

Brickwork bonding patterns:

·      English Cross bond

·      English bond

·      Flemish bond

·      Stretcher bond

·      Monk bond

·      Stack bond

·      Header bond

Clay brickwork is porous and naturally vulnerable to potential damage from freeze thaws

Soluble salt is naturally present in clay and therefore all clay bricks contain some level of salt content.

Standard brick size: 215 x 102.5 x 65 mm

Common mortar joints:

Bucket handle joint

With struck joint

Flush joint

Recessed joint

Causes of movement in brickwork:

Moisture content and variation

Thermal expansion

Sustainability

Slimmer bricks or manufactured brick slips = less material and less fuel to fire

BS8000 = how to handle brick safely

BS EN 771-1: 2011+ A1:2015 = specification for clay masonry units

LIGHTING

Types

·      De-mystifying light

·      Temporary light

·      Flat light

·      Refracted light

·      Bokeh

·      Infra-red light

Indoor lighting

Social

Airy

Spacious

Outstanding

Legible

Soft

Warm

Safe

Transparent

Inspiring

Comfortable

Outdoor lighting

Social

Airy

Exterior lighting

Hard to control – variation between day and night, as well as seasons

No ceiling – Zero reflectance, light pollution

Hostile environments – Weather, vandalism

Require different light levels

Balance of light levels

Urban environment – high

Suburban environment – medium

Rural environment - Low

ECOLOGY

This lecture was particularly interesting to me as I’m very interested in ecology and wildlife.  It would be very helpful when looking at existing and potential species and habitats on my site, and help with the formation of a habitat and biodiversity plan.  It was also helpful to recap the principles of biodiversity again and given that my site has very little biodiversity or vegetation, should be easy to achieve this with redevelopment.

Concept principles and approaches:

Ecology is the study of relationships between living and non-living parts of the world

Biodiversity = variety of living species (plants, animals, bacteria, and fungi)

Ecosystem = plant and animal communities (+ non-living elements such as soil) interacting as a functional unit

Usually grouped in relation to habitat types such as woodland, grassland, etc.

Nature conservation = policy and practice of conserving ecosystems and biodiversity for cultural, aesthetic, economic, or scientific reasons

Woodland – birds

Grassland – butterflies

Coastal – Little terns

Biodiversity Net Gain

ABC of BNG

Steady decline in biodiversity since the 1970s

Lost 90% of wildflower rich grasslands

Intensification of agriculture and development – loss of existing habitats

BNG deters development from damaging or degrading existing wildlife habitats

SuDS – SUSTAINABLE DRAINAGE SYSTEMS

What are SuDS?

Systems managed surface water run-off in a way that mimics natural processes

They aim to slow down, store, and treat water close to where it falls

They reduce flooding, improve water quality, and enhanced biodiversity

Components

Source control – managing water at the source such as rain gardens and green roofs

Conveyance feature – movement of water slowly across the site such as rills and wails

Storage feature - temporary storing of water to prevent flooding such as detention basins and ponds

Treatment feature – removes pollutants such as wetlands and infiltration trenches

Benefits:

Flood risk management – reduce run-off rates and volumes, protecting urban areas from flooding

Water quality improvement – remove sediment, oil, and heavy metals from surface water run

Biodiversity and habitat creation – supports pollinators, birds, and aquatic species

Urban cooling – reduces urban heat island effect

Aesthetics and recreational value – creates pleasant environments for communities

Common features

Swales

Rain gardens

Permeable paving

Ponds and wetlands

Detention bases

Rills and channels

What is a permeable modular pavement?

A pavement consisting of paving unit units laid with white joints, voids or openings allowing water to pass through the pavement surface course and into either the supporting construction an adjacent drainage device

Permeability

The degree to which water can pass through a material

Infiltration

The rate of which volume of water can pass through a given area of payment

Unbound construction

Blocks or sets with 2 to 6 mm graded hard angular aggregate filled eight mm wide joints

Bound construction

Blocks sets, slabs flags, pavers and porcelain with 12 to 20 mm permeable motor to joints

Why do we need SuDS?

Climate change and changing seasonal patterns of rainfall (volume/intensity)

Impermeable surfaces/ urban growth/ increased run-off rates

Existing drainage infrastructure is overwhelmed

Increased pollution risk

To attenuate run-off

To limit run-off

To increase quality of infiltrated water

Environmental benefits:

water quality

PH neutralisation – acidic rainfall = pH 5.  Discharge pH = 7.5

Filtration of sedimentation – organic material biodegrades

Absorption – heavy metals trapped and retained indefinitely

Hydrocarbons - trapped and degrade

Considerations

Hydraulic function – moisture management

Structural function – pedestrian/ vehicle traffic

Aesthetic function – unit type, joint size ratio

BIOENGINEERING

Bio engineering solutions

Nature based solutions

Soil erosion control

River restoration

Carbon equation

Natural flood management

Blue green infrastructure solutions

Wetland habitat creation

From mountains through a freshwater via wetlands: to improve water quality and create new habitats using the power of plants and natural processes for wildlife and people, restoring marine habitats, replacing hard engineering with soils and vegetation, restoring lifeless and toxic environments, restoring natural processes helping save declining wildlife.

River processes

Geomorphology

Hydrology

Ecology

Benefits of soil bioengineering

Improves water, quality and sediment accretion

Uses less CO2 than hard engineering

Nature based solutions – create/modify natural or naturalistic features in the landscape that are designed primarily to provide benefits for human well-being such as flood management or carbon sequestration, which also contribute to the improvement of ecological networks and biodiversity conservation