Highbury

Passive House Principles 3 Storey Side Extension with Compact Unit

Design

Ian Taylor

Project Description

The client who is also the architect was looking to build a Passive House quality side extension to his home and contacted us directly due to our experience in this field. Due to an unfavourable form factor – the ratio of building volume to surface area – resulting from site constraints, Passive House could not be achieved however we endeavoured to get as close as possible using Passive House design principles.

We achieved this by building a timber frame structure heavily insulated with rigid board and expanding foam with a brick exterior to meet planning requirements. We fitted high performance windows and a Nilan combined MVHR unit and domestic hot water system. We provided full mechanical, electrical and insulation design and installation. Due to very low heating demands and project cost restrictions we used underfloor electric heating mats throughout.

The extension consists of two bedrooms, two bathrooms, a snug and a kitchen diner. The small building width was very restrictive, there was pressure to retain and maximise internal space, storage potential and to utilise every recess. This resulted in curved walls to increase the feeling of space.

A Loxone smart home system controls heating, MVHR system, & light switches. It was designed with a future provision for control of electric blinds.

“Prewett Bizley and Bow Tie Construction worked very well in partnership which made our lives very easy.”

– Francis M
“Rafael is very familiar with the latest building technologies and is always on hand to offer suggestions and advice on the practicalities of achieving the desired end product.”

– Brian A
“We’re expecting a dramatic reduction in costs. We now know how much energy we’ve used (in March) and we rarely have the heating on compared to this time last year in our old house.”

– Toni M
“I have enormous respect for Bow Tie as a contractor: It’s a real pleasure not having constant battles and headaches from a builder trying to do the bare minimum.”

– Justin Bere
“This house is cosy and comfortable but in a natural way. Our old house was of similar scale, area and build and if you wanted to heat a room you had to blast it and the air would then be very dry and that heat would quickly leak out.”

– Toni M