Passivhaus Affiliate

Verlands Road receives Passivhaus certification

Designed by PHT member Sarah Small Architects, the 216m2 contemporary new build home accommodates 6 people and received Passivhaus certification in March 2017. The south facing site has far reaching views across Weymouth Bay and is the first Passivhaus in the region.

Verlands Road Passivhaus, South Elevation  Verlands Road Passivhaus, North facing elevation

All images ©Sarah Small Architects

Sarah Small Architects gained planning approval to demolish a 1960’s bungalow and rebuild a two-storey detached house. The approval to demolish and rebuild gave the client the opportunity to achieve something different and the design was then developed to meet Passivhaus standards.

After going out to tender to four local builders, which all came back over budget, the decision was taken by the client to go down the self-build procurement route. Sarah Small Architects was employed to measure and order materials, act as cost consultant, to provide daily on site supervision, and to obtain quotes for each element and ensure suitability of all trades.


It was necessary to be on site everyday to make sure each contractor knew about building to Passivhaus standards. We found this to be important when installing the airtight layer. Sometimes it was necessary to pick up the tape and demonstrate how the membrane should be taped, especially around the window reveals. We under estimated the amount of tape needed, and the time it takes to carefully cover every inch of the building. 

Sarah Small Architects 


The detached timber frame home has a Valliant EcoTec plus 612 gas boiler and Paul Novus 300 MVHR unit. The new house has a high standard of finishes throughout; Materials include cedar cladding, zinc roof & polished concrete floors.

Verlands Road Verlands Road, Gable Verlands Road south facing kitchen

This was a Passivhaus first for all the team. Both the client and architect wanted to push building standards and educate the building industry. Sarah Small Architects are pleased with the execution of the passivhaus design into built form, and are keen to use their experience and knowledge on future schemes.

One of health benefits to living in a passivhaus is the comfortable, fresh and clean environment internally. The house has maintained a constant internal temperature of 20°C over the last winter, when external temperatures dropped to -5°C.  Noticeably one of the children occupying the new house used to suffer several chest infections each winter, and remarkably has not suffered one since moving in.



Building Performance

n50 ACH@50pascals (≤0.6ach@50pascals)


Thermal Energy demand (≤15kWh/m2.yr)

10.3 kWh/(m2.yr)

Thermal Energy load  (≤10W/m2)

10 W/m2

Primary E demand (≤120kWh/m2.yr)

110 kWh/(m2.yr)


Key Team


Client: Private

Architect: Sarah Small Architects

Consultants: Williams Energy Design

Structural Engineer: Roger Locke Consulting       

Certifier: WARM



Further Information

Sleepy Dorset blog

Verlands Road Passivhaus

23rd June 2017

< Back To News