Founded in 1992, A D Practice Ltd is a small, well-established and multidisciplinary Chartered RIBA architectural practice located in The Mill, Wheathampstead, Hertfordshire.
We offer a full range of design services including specialised planning advice and design development; initial feasibility studies; planning permission consents and appeals; building regulations; sustainable design; energy efficiency advice; contract administration. We also offer Passivhaus design and are members of the Passivhaus Trust and The Green Register.
Our key strength is our ability to listen and learn from our clients and work together in order to create better spaces that both work for people and improve their quality of life. We design in BIM (Building Information Modelling) meaning that we can offer 3D visualisations of all our schemes, no matter how small, which can aid the understanding of the design for both clients and planners.
Sustainability is at the heart of this philosophy and every design we produce. As members of several sustainable building associations and Certified Passivhaus designers, we design buildings that are healthy for both the planet and occupiers, using natural construction materials and renewable energy sources where possible, minimising the energy used by our buildings and setting them sensitively in nature to maximise natural daylighting and enhance local biodiversity.
We have a varied client base from both the public and private sectors, commissioning bespoke and developer-led schemes.
Completed work includes individual residential new-builds and developments; extensions and refurbishments; commercial schemes; conservation and listed building work; primary, secondary and tertiary level education projects; restaurant and retail fit-outs; ecclesiastical; healthcare and community projects.
Wheathampstead
England
AL4 8DT
United Kingdom
Deep retrofit of a 1960s detached house in Harpenden and the addition of a small rear extension.
This project is certified as meeting the EnerPHit Plus (Passivhaus) retrofit criteria, the third such project in the UK, and is ‘gas free’, using an air source heat pump and harnessing renewable energy with an entire roof pitch dedicated to solar pv.
The existing brickwork walls were externally insulated using wood fibreboard and finished with a painted render and the curtain walls were removed and replaced with new highly insulated timber I beam walls with cellulose insulation and clad in larch. The rear single storey extension was also constructed in this way and finished with either render or timber cladding. The existing ground floor was removed and replaced with a new highly insulated slab with underfloor heating.
3 new Passivhaus Plus dwellings are constructed from prefabricated timber frame panels. The south and the west-facing roof slopes use solar panels as the roof finish which reduce the energy demands of the houses and supplement the hot water requirements, the rest of which is provided by air source heat pumps, so the properties ‘gas free’. Walls are finished in a mixture of render and western red cedar cladding which ties the properties to their position on the edge of woodland and provides a sustainable and breathable construction solution. Non-solar roof slopes are finished in slate.
All 3 properties make the most of the natural light available on the site through the clerestory windows and having tall strip windows and voids through the floor plates, ensuring that as much light as possible reaches into the middle of the ground floor, providing an excellent internal environment for the inhabitants which is coupled with MVHR system, creating a very healthy living environment.
Deep retrofit of a 1960s detached house, new roof and mezzanine space and internal alterations. This project is the first retrofit in the UK to be certified to Passivhaus Plus standards. The house is ‘gas free’, using a ground source heat pump and an entire roof pitch dedicated to solar pv.
Existing brickwork walls are externally insulated using wood fibreboard which is finished with a painted render and vertical Brimstone Ash cladding and new first floor gable walls have been constructed timber I beam walls with cellulose insulation and clad in vertical Brimstone Ash cladding. The existing roof was removed and turned through 90 degrees and new roof constructed in a similar way as the new walls, forming a gable at the front and rear, making the most of the views across the garden and countryside behind. The existing ground floor was also removed and replaced with a new highly insulated slab with underfloor heating and cooling
