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This proposal is for two exemplary Passivhaus houses in the BRE Innovation Park represents the culmination of a dream and the start of a new era.

Each of the two houses is designed to be adaptable as a terrace house in an ordinary infill street site. Both the Social housing dwelling and the market sales dwelling have an open plan living/dining/kitchen on the ground floor with a WC off the hall.  The social housing dwelling is of two storeys and designed to meet all HCA and Lifetime Homes standards. The market house is designed so the living room and hall are double height volumes providing a dramatic interior quality as well as allowing the sunlight to penetrate deep into the space. These spaces will also be utilised in the design of the ventilation system to optimise the stack effect. Both houses are to be designed to Level 4 of the CSH and to certifiable PH standards.

The proposed construction minimises thermal bridges, utilising a panelised form of superstructure over-clad in insulation and finished in render. The budget set for the project has been a major influence over the specification. Timber has been selected as the main structural frame as it is sustainable and has a low CO2 impact. The insulation filling can be sourced from recycled materials or from natural sustainable sources. The frame would be supplied as a factory component, so that the energy and the waste to produce it can be controlled. This is more efficient than a site based fabrication.

The south elevation rooms would be provided with permanent solar screening or flexible vertical external blinds to windows. The louvres spaced to provide optimum outlook would be designed to maximise the solar gains in winter while reducing gains in high summer months. This device coupled with night time ventilation in summer will prevent overheating and add to internal comfort levels at other times of higher solar activity.

The Brise Soliel was selected to cover the entire southern elevation, the green roof was built into the model and a living wall was built into the external wall of the second floor of the market house. While green roofs and living walls are not considered when calculating the U-values of a construction element, they increase the thermal mass of the building and consequently slow heat build up within a building during the day, reducing peak internal temperatures.

By its very principles, the Passivhaus concept embedded into the whole building design will make a significant contribution to lowering the CO2 impact of the building over a 60 year life Cycle.


127 Banbury Road Student Accomodation @ Oxford


This Victorian House in North Oxford Conservation area was in a dilapidated condition. The brief was to extensively refurbish and provide additional accomodation for the Warden. The refurbishment included cleaning and repair to stonework and brick, restoration of stained glass window and a new extension closely matching the existing building’s character.

Due to the age of the building, it required a specialised solution to deal with the solid external brick walls. The solution was to dry line the inside face of the external walls with Dry Therm to improve the thermal value without altering the original character of the external appearance.

The refurbishment also included new double glazed sash windows to replace the original single glazing. Additionally, solar thermal panels and low energy lighting were installed to boost the sustainability of the project.

Overall the refurbishment gained a total of over 50% energy savings.


House in Delgany, Co Wicklow, Ireland

Photo taken by Client recently.
(Note the storm porch which is outside the Passivhaus envelope for the purposes of PHPP assessment)


This is a single family dwelling house being constructed to a Passivhaus Standard south of Dublin close to the coast. We were approached by the client to provide advice on how to achieve a Passivhaus within the constraints of a design which already had planning permission.


The new house will form part of a larger development. The client as part of a land swop arrangement through the sale of the development site secured the most prominent building plot for his own use.


PDS have provided design advice from the beginning of 2011, this has included internal re-planning and support for a hybrid self build/partnership with a local builder. Assisting the client with the specification PDS has worked with key suppliers and subcontractors to deliver the envelope and framework to complete a house that will meet Passivhaus requirements.


The house design incorporates a fully insulated under slab system with a load bearing reinforced concrete ground floor to deliver thermal mass to counter summer over heating conditions. An open panel timber frame superstructure with full fill void insulation and fully timber boarded internal lining to walls and roof to provide the Air Tight Layer (ATL).


Joints in the timber lining are reinforced and sealed with tape to form the ATL. Rigid close cell insulation is provided to the external face of the timber frame and this in turn is boarded for render or cladding finishes.

• Windows are triple glazed uPVC, with colour and timber texture finish.
• Internally the frame will have a service void lining to external walls protecting the ATL and avoiding the need to penetrate the timber internal lining.
• Elemental U values exceed the minimum standards set by the Passivhaus Institute. The values for heating energy demand as calculated by PHPP are predicted for the house to be below 10kWh/m2a.
• First stage air leakage testing following the completion of the frame and installation of windows/doors has achieved the Passivhaus standard of 0.6m2/hr/m3@50pa, despite clear leakage from a couple of window joints. The house will be tested again following completion of services and again at completion.


We have further work to do before completion at the end of 2011 to fine tune the services and ventilation provisions.

The client has worked closely with us and has expressed his deep satisfaction with the advice and assistance provided by PDS.

It is hoped that the client will be able to occupy by the end of the year, to take the full benefit and comfort of living in a Passivhaus.