• Eco refurbishment and extension of 1960′s house in Grayshott, Surrey
• Assessed using Passivhaus software and designed to AECB Carbonlite Silver Standard
• Specific Space Heating demand as existing 278 kWh/m²a, as proposed 38 kWh/m²a
• Air leakage as existing 11 air changes per hour, target 3 air changes per hour
• Improvements include external wall insulation using wood fibre, constant running mechanical extract ventilation, Katzbeck triple glazing
• Main contractor John Brown Project Management

We have been using our Passivhaus experience to help detail this stunning new low energy country residence located outside Maidstone in Kent, which is to be built to Code Level 6, possibly the most ambitious dwelling ever built in the UK to such a standard. Being built to Code Level 6 means it is close to being carbon neutral, although this subject is hotly debated in eco building.

It is being built under PPS7 which is ‘an isolated new house in the countryside ….. clearly of the highest quality, is truly outstanding in terms of its architecture and landscape design, and would significantly enhance its immediate setting and wider surroundings ….. The design of such a house should be ground breaking in its use of materials, methods of construction or its contribution to protecting and enhancing the environment…..’

• New detached house designed to Passivhaus standard, currently being certified
• Designed with repeatability and efficiency in mind
• Timber frame
• Triple glazed windows
• Super insulated to minimise heat losses and maximise passive solar gain and natural day lighting
• Solar thermal to provide hot water
• Photovoltaic panels to generate electricity
• Self-build, currently under construction

Following on from our work with SPAB on insulating old buildings, we advised architects Purcell on the best method of upgrading walls and roofs at Knole House, as part of repair and improvement work being undertaken by The National Trust.

We undertook U value and interstitial condensation calculations, using weather data gathered on site over the last 2 years.

As with all historic buildings, preservation of the fabric is the main priority.  In some cases introducing insulation would increase the interstitial condensation risk, in which case it is better to avoid insulating.  This shows the importance of careful analysis.

Selecting the appropriate materials and carrying out the work to a high standard are equally important.

• Former World War 11 RAF Hut restoration and extension.
• Property in an Area of Outstanding Natural Beauty (ANOB) and Special Landscape Area (SLA).
• Original parts clad in corrugated steel sheeting reflecting the historical military association of the building and local area.
• New extension clad in oak weatherboarding making a clear visual demarcation between the original and new build.
• Selfbuild.

• Highly sensitive design evolved with client, Ashford’s Conservation Officer and English Heritage
• Provides private access to apartments to avoid use of 17th century main stairs
• Complex internal alterations to WC and bathroom

• New family home in Conservation Area
• Designed by client (Architect and Conservation Officer)
• Uses traditional materials including brick, flint, clay tiles, and timber cladding
• Conker provided energy performance calculations using Passivhaus Planning Package, and produced the detailed design, calculated to achieve a specific space heating demand of 15 kWh/m²a
• House uses triple glazing, heat recovery ventilation, and a tiny gas boiler to heat ventilation air and towel warmers

• Replacement dwelling in AONB (Area of Outstanding Natural Beauty), in an exposed location
• Client’s brief was for a traditional appearance but exceptional thermal performance, at a sensible price.  Therefore a simple and efficient plan and shape was adopted, with a porch to mirror the original
• The new design meets Passivhaus criteria for heating load, based on super insulated walls, floor, roof, triple glazed windows, mechanical ventilation with heat recovery, solar shading
• Designed so there is no need for central or underfloor heating due to tiny heating demand

• Self build elliptical 2 storey straw bale house
• Larsen trusses support main roof loads
• Straw bale infil for insulation
• Internal tower of dense masonry provides thermal mass
• Green Roof
• Reed bed sewage treatment and rainwater harvesting
• Locally made double glazed oak framed windows

• Semi detached house, typical of the era, with a mixture of cavity and solid walls
• Eco refurbishment and energy efficiency improvements
• Extended to the side, 2 storeys, and given a thorough range of thermal improvements
• Front cavity wall widened to accept 225mm of insulation
• Rear insulated with 200mm of wood fibre and lime rendered
• Heat recovery ventilation, solar PV, solar thermal, triple glazed windows and built in bat and bird boxes

• 1930′s detached house, of cavity and solid wall construction.
• Extended to provide additional bedroom, new kitchen, and spacious family room overlooking garden.
• Existing house insulated and upgraded, typical U values 0.15 W/m²K.
• Energy calculations carried out using Passivhaus software, the eco refurbishment was based on EnerPhit principles.
• New triple glazed windows.
• Contractor: Kithurst Builders

• Eco refurbishment assessed using Passivhaus software and based on the EnerPhit principles.
• External wall insulation using 200mm expanded cork, finished with lime plaster.
• Roofs upgraded with 50mm polyurethane between rafters, plus 200mm sheeps wool under, with vapour control layer and plasterboard.
• New passivhaus certified triple glazed aluminium/wood windows.
• New comfort ventilation system (MVHR) from Itho.
• Thermal bridges and air leakage were carefully addressed and rectified.  Air leakage was reduced in excess of 10 ach down to 2.8 ach.

• New village hall designed by Conker to replace existing hall which suffers from severe structural problems
• Located in the Green Belt and therefore comprehensive supporting documentation was produced to justify the Planning Application
• Consultation with village residents led to a traditional design, which blends local materials and roof pitch with modern windows and thermal performance
• Currently fund raising.

• Low energy sustainable classroom, designed in collaboration with C P Associates for King Edward V1 Humanities College in Lincs.
• Constructed from Hemcrete by Lime Technology Ltd
• Rammed earth mass wall internally, designed by Ram Cast CIC
• Full mechanical ventilation with heat recovery.
• Northlights for high quality daylight.
• Recycled plastics by Smile used for desktops and splashbacks.

• New detached house with basement, timber framed with flat roof.
• Designed to avoid overlooking and privacy to over 30 neighbours.
• Recommended by Swale Borough Councillors who commented “we should be honoured that our borough has been chosen as one of the first to have this kind of building”.
• Currently being certified, works in progress.

• The UK’s first certified light industrial Passivhaus.
• Constructed using timber I beam portal frames without any tie members, giving a totally free interior volume.
• Heated by a wood pellet boiler on a district heating circuit.
• Airtightness 0.36 ach at 50 Pascals.
• For further details please see the Internal Passivhaus Database

• Total refurbishment of 17th century farmhouse from a derelict state into a comfortable office space for Kent Wildlife Trust staff.
• External wood fibre insulation and lime render replaces 3 to 4 layers of cement render.
• Rainwater harvesting serves WC’s and irrigation system.
• Low solvent paints, natural fibre floor finishes, recycled plastic worktops, recycled car tyre entrance mats complete the project.

• Built in an area of protected woodland
• Minimal foundations to prevent damage to tree roots
• Replaces dilapidated sheds
• Constructed with timber felled on site
• Craft and nature room constructed from straw bale infill using straw from adjoining farm
• Methods of construction allowed non skilled labour of volunteers and rangers to contribute extensively to the work

• One of our longest standing clients, a wonderful centre for school children to learn about their environment.
• We have designed a straw bale classroom block which compliments the historic main building.
• Main frame from reclaimed douglas fir, machined and erected by Norton Timber
• 8 years on and funding is still not available to complete this project.  Next phase – windows, internal fit-out.

• Costly render repairs made external wall insulation a financially viable option, for this hard to heat end of terrace 3 storey house.
• A combination of 200mm and 100mm external insulation was used, with internal insulation to the sensitive front elevation.
• Combined with solar thermal and a new boiler, energy consumption has reduced by 60%.  The property features in the SEA’s Superhome database.
• Even in a historic conservation area such as Faversham, thermal improvements are possible, if carefully thought out.

• Grade 11 listed house in Rye’s central conservation area.
• Rear extension to form kitchen, dining, bathroom and ensuite.
• Repairs to existing solid and timber framed construction, using appropriate materials.
• Thermal insulation using appropriate materials, rainwater harvesting, solar thermal, central ventilation unit.
• Conker Conservation carried out the survey, design, planning application, building regulations, specification and tender.  Client project managed work on site.

• A delightful cottage which existed long before Margate’s expansion, with flint walls and peg tile roof.
• We arranged major roof repairs, and roof insulation works, using SPAB’s latest guide on Kent Peg Tiles.  Most of the tiles were reusuable, apart from the newest ‘Rosemarys’ which were defective.
• Works were carried out on budget by S & T Fullers Builders Ltd, with the owner in-situ.

• An affordable, simple and functional new house for a farmer who has lived in a caravan for 17 years.
• Timber frame, double-glazing, cork cladding, under a ‘brown’ roof.
• Energy efficient buildings need not be complicated or expensive.

• Former poison shed converted into an energy efficient annexe
• Internal wall insulation, warm roof construction and fully insulated floor
• Underfloor heating via condensing gas boiler. Solar thermal hot water. MVHR. Rainwater harvesting

• Self-build to Passivhaus standard, under construction
• Traditional design in area of outstanding natural beauty
• Detailing designed to be suitable for self-builder
• MVHR and solar thermal

• Designed to avoid overlooking and privacy issues with neighbours
• Built using both cavity wall construction and timber frame
• Air tested prior to completion at 1.0m³/m²hr
• Passivhaus standard U values, avoidance of thermal bridges, MVHR, rainwater harvesting and solar ready

• Dilapidated house in conservation area with Article 4 Direction.
• Building underpinned, stitched and tied together.
• New 2 storey side extension, single storey rear extension.
• Glazed link between new and old.
• Thermal upgrade using natural materials.
• Much of the work carried out by the client.

• Survey and feasibility to determine sustainable and economic roof recovering
• Design and specification of system incorporating natural cork insulation and recyclable PVC-free single ply roof membrane
• Oak decking
• Sweet chestnut decking
• Costings and advice on ecological refurbishment of office

• Rammed earth walls utilising clay sourced from the site with locally sourced aggregate
• Green roof system
• Passive solar design
• All materials selected to be sustainable and to provide a harmonious internal environment
• Undertook all design and specification
• Contract administrator

• Replaces dilapidated bungalow in Area of Outstanding Natural Beauty
• Considerable planning research/liaison required due to very sensitive area
• Design developed to minimise visual impact and heat loss – very exposed site
• Super insulated walls, floor and roof, partially earth sheltered with planted roof
• Maximises solar gain with dense internal walls for thermal mass
• Design has received Ashfords ‘Building Design and Construction Award 2009, Residential Development category’

• Unusual front extension recommended due to restrictions at rear
• Steeply sloping site enabled a lower ground floor to be added
• Property within a Conservation Area, much research/liaison required
• Achieved much improved access from street level
• Design and specification of materials critical due to client’s chemical intolerance

• Earth bermed circular construction using rammed chalk walls with vaulted tiled domed roof and vaulted internal staircase
• Researched use of chalk as wall material, and specialist products such as ‘zero-energy’ cork and timber triple glazed windows
• Incorporates holistic approach to design, materials and construction
• Undertook all detailed design, obtained planning and building regulation consents and acted as project manager

• Remains of a barn in in dilapidated condition
• Amended existing planning consent and obtained approval of planning conditions
• Obtained building regulation consent for conversion
• Obtained planning permission for conversion
• Extensive timber repairs required – sensitive to historical fabric
• Design incorporated use of traditional materials and construction methods

• Grade II listed dwelling requiring refurbishment
• Extensive liaison required with Conservation Officer
• Designed and specified use of traditional construction materials eg; wattle/daub, lime rendering

• Replaces disused garages in heavily built up area
• Planners had previously refused permission for conventional house submitted by the developer
• Evolved contemporary design following liaison with local residents and local authority
• Design has since received a ‘Green Apple’ Award, ‘National Silver Winner, Small Residential Project’