Passivhaus Consultant and Designer, Bristol.  Very Low Energy Buildings.  Domestic and non-domestic.  New build and refurbishment. 

07502 425158

Bristol, UK


Entries in Refurbishment (27)


Another Listed Building needing an Energy Upgrade

This Grade II Listed former textiles mill is undergoing a change of use to residential use with groundfloor office space.  We are working with Greenheart Sustainable Construction to develop the detailed plans for the conversion, making the building energy efficient and comfortable to live in, whilst being sensitive to the buildings heritage.  

Insulating old solid walled buildings needs to be done with care and a whole house approach will be taken to include insulation, wiondow upgrades, airithghtness, ventilation, heating and hot water.  

The fundamental strategy is to select appropriate, mainly natural, building materials and get the ventilation and vapour control right.



Grade II* Listed Building Refurbishment

We have recently been appointed to advise on servcies and roof insulation for this Grade II* Listed house.

The heritage value of the building dictates most of the works with restoration as the main driver.  The focus for energy efficiency is on insulating the roof and providing energy efficient heating and hot water.

We are advising on design and procurement of a 50kW water source heat pump with oil backup for heating and hot water.  



The geometry of the roof, combined with the historic structure makes insulating the roof effectively without risking damage highly challenging.  





Room in Roof Insulation - a risky business

The complex geometry and construction of room-in-roof settings, especially in older houses, makes them very difficult to insulate with appropriate vapour control and without risking interstitial condensation and potential building damage.  


Similar issues in relation to solid wall insulation are well documented and solutions presented in the excellent new 'A Bristolian's guide to Solid Wall Insulation'.

Piers has been grappling with this on a number of projects and produced a blog post for the Green Register describing the problem and recommending an approach that addresses most of the issues.


Reedley Road - performance gap eliminated

Predicted specific heat demand 36 kWh/m2/yr.  Actual specific heat demand 24.5 kWh/m2/yr.

This Passivhaus inspired refurbishment project exceeds the design expectations with over 80% of the heating provided by a wood burner in the kitchen/living area.   The specific heat demand is just below the threshold for the Passivhaus refurbishment standard EnerPHit.

Come and see it at Bristol Green Doors 26 September 2015. 

Reedley Road Design Stage PHPP Modelling



Our houses on show at Bristol Green Doors 26 September 2015

EWI back of Toronto RoadCome and see the completed Passivhaus inspired refurbishment at Reedely Road and the almost complete refurbishment at Toronto Road at Bristol Green Doors.