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Kensal Green Passive House

Total Refurbishment and Upgrade to Full Passive House with Solar Panels
Eco Design Consultants
Contract Value
Circa £300k
Project Description

Having been refurbished to the full Passive House standard this is now one of the most energy efficient houses in London and one of the most energy efficient Victorian houses in the UK.

The developer had owned the house for some time, and planned to sell it. But before he did so, he wanted to make the house as energy efficient as possible as he feels a responsibility to cut the emissions from any property he has an influence over. We feel that he would have been better off in terms of money and time spent on the project had he opted for EnerPHit, but he wanted to go full Passive House, so we were determined to achieve that, and we did.

Building good relationships with clients is paramount for us. We are passionate about Passive House and will always work with clients to develop their ideas and deliver their project. In this case Mr.Land advised us early that he could only fund around 2/3 of the building works prior to sale. Together we developed a strategy so that Bow Tie Construction could carry out the works without risk to anyone until the house could be valued and re-mortgaged in its completed state. We don’t think there are many builders who would agree to this and we hope this demonstrates to our clients that we are dedicated to their cause.

As part of the upgrade to Passive House, the whole property was deep refurbished. The ground floor now has a polished concrete floor throughout, open plan kitchen and dining room and open plan living room. The 1st floor features two bedrooms and a family bathroom. It is where the MVHR unit is housed. A PAUL Focus 200 unit and all ducting were installed. The system was designed by Green Building Store who now recommend us for all their London MVHR installs.

The Loft was converted to provide a master suite with a large bedroom and shower room. The flat roof of the rear mansard is constructed from durable fibreglass.

While planning permission for external wall insulation was initially denied, Eco Design Consultants lobbied the local authority until it was later clarified as a permitted development, providing the appearance was maintained. This has set a planning precedent for the area. Using EWI gives a better performance than Internal insulation, reduces moisture risks and does not decrease internal space.

A 250mm thickness of EWI was required to meet the Passive House standard. This took 3 layers of board and special long anchors. The EWI was then finished with render.  Window reveals were also insulated internally. Green Building Store Passivhaus triple glazed windows and French doors with insulated frames and an ULTRA entrance door (insulated with VIPs panels) were fitted.

Loft level party walls were insulated internally. Roof rafters were replaced and insulated with Icynene spray foam, which fills all gaps and creates an airtight breathable insulation layer. We always recommend Icynene for roof insulation.

The floor was excavated and insulated with 300mm of Expanded foam and topped with a polished concrete slab holding the underfloor heating pipes.

When the project was in its final stages the client decided to add PV panels to the roof. We were happy to make the necessary design and construction changes to allow this to happen.

The garden features wooden decking and a living wall. This now an extremely cosy house occupied by a family, we hope to give a report one year on so they can tell us what it is like living in a Passive House through winter.

  • “The house definitely meets expectations and exceeds them in some areas, the heat comfort is very big, the noise is much less than it was, overall very happy with it.”

    – Francis M
  • “We’re really lucky to have Bow Tie Construction working on our project. Thanks for all your fantastic work so far.”

    – Nick H
  • “I’ve been very pleased with how Bow Tie have got on with the work.”

    – Justin Bere
  • “I did get the benefit of regular updates and involvement in the project so I could see the quality of the work.”

    – Raza Rizvi
  • “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

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