Lime Tree Passivhaus

An oak frame newbuild 3-bed home was designed by oak frame specialists Oakwrights and built by Furber Young Developments for clients Andrew and Linda Burnett in rural Worcestershire. The project has achieved Passivhaus certification and is due to open in the summer of 2021 as a B&B, offering visitors a unique chance to experience living in a Passivhaus first hand.

21° designed and supplied the MVHR system and the ULTRA triple glazed timber windows and doors for the project.

Design

The clients were keen on the character and aesthetics of exposed oak timber frame and during their research phase talking to Oakwrights they became aware of the Passivhaus low energy standard. The Burnetts visited other Oakwright oak frame Passivhaus projects, which confirmed their decision to opt for the comfort and energy saving benefits of Passivhaus. After much searching, the Burnetts found a plot for their selfbuild within an Area of Outstanding Natural Beauty near Malvern in Worcestershire.

Oakwright’s Passivhaus design team worked with the Burnetts to meet their aesthetic as well as low energy requirements. The house has two south-facing gable ends with four strategically positioned lift and slide doors to take advantage of the beautiful views. Balconies and shading strategies help manage any overheating risk and the balconies on the upper floors are open-roofed but with optional blinds which provide shading when needed. The house is designed ‘upside-down’ with the B&B bedrooms on the ground floor and living area upstairs to make the most of the views.

To achieve the Passivhaus standard the oak frame was encased with Oakwrights’ WrightWall and WrightRoof Natural encapsulation panels, which offers high levels of airtightness. To meet the minimal heating requirements of the Passivhaus standard the commonly-seen gabled ceilings of an oak frame house needed to be truncated a little to achieve a suitable internal volume. However, the Oakwrights design still provides high ceilings, a sense of openness (especially in the double-height hall) and the enormous number of exposed oak beams provides interest and focal points creating a unique aesthetic. 

The project achieved 0.57 ach / hour @ 50 Pa and has a certified space heating need of 13 kWh/m2/ year.

MVHR heat recovery ventilation

21° worked with the Oakwright’s team to develop an MVHR system that would work alongside the encapsulation system. A Zehnder ComfoAir Q MVHR unit with rigid steel ducting was specified for the project.

Triple glazed timber windows & doors

21°’s ULTRA triple glazed timber windows and doors, including four Lift & Slide doors, were chosen for the project.

We have been really impressed with the windows and doors and the customer service we received from 21°. The quality of these products and the precise installation was crucial for the airtightness of the project ultimately contributing to our Passivhaus certification. 21° worked closely with Oakwrights and the builder Furber Young Developments on the design and installation of the windows. 21° was very helpful in calculating the optimal position for the windows within the Oakwrights’ WrightWall and WrightRoof Natural encapsulation panels from a thermal bridging and airtightness perspective. We also appreciated the fact the 21° could fit the windows and doors and not just supply them. Proper installation is vital to fully exploit the advantages of triple glazing.

Andrew & Linda

One of the main reasons we chose to use 21° for our windows, doors and the MVHR system was their Passivhaus expertise and knowledge, which has been a great help and support throughout our Passivhaus selfbuild

Andrew & Linda

Visit Woodlands

Woodlands is the UK’s first oak frame certified Passivhaus B&B and will be opening for visitors from early July 2021. More information: Woodlands Passivhaus B&B

Project details

Completed

2020

Case study

2021

Change the way you think about energy