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Renewable Energy New-Build:

Passivhaus Standards, High insulation, Renewable energy generation
Download Printable Case Study (PDF)

Overview

Floor Area: 220m2
Location: Chew Stoke, Somerset
Project Duration: April 2018 – April 2019
Type: Timber clad replacement dwelling. Timber-frame.
No. of Residents: 4 Humans, 1 Dog
Conservation Status: Within Bath & Bristol Greenbelt

Key Features

Passivhaus Standards

High Insulation

Triple Glazed Windows

Airtightness

Mechanical Ventilation w/ Heat Recovery (MVHR)

Solar PV tiles with Battery

Energy efficient appliances & Lighting

Orientation
Eco-ready wood burning stove
Solar Hot Water Cylinder

Electric Car

Introduction

Christin Peglow and David Archer were motivated to create a sustainable and contemporary family home with spaces that connect internally and externally.

The house was purchased as a previously extended and poorly functioning 1960s dwelling in 2014. It was purchased as a project to be a new family home with an intention to refurbish it as sustainability as possible.

Following the pre-planning enquiry and costing of the initial re-furb option, the family decided to start fresh with a replacement dwelling due to planning restrictions withing the Greenbelt, a compromised remodelling option and VAT saving on a new build.

Christin, one of the homeowners, is an architect and hence the decisions were founded on professional knowledge. They project managed the build themselves following recommendations for a pre-fabricated timber frame and local sub-contractors.

The New dwelling was built between April 2018 and April 2019.

Aside from the previous motivations, the benefits of the re-build included, cost savings and climate consciousness.

Features

  • Constructed to Passivhaus standards:
    – Insulation
    -Airtightness
    -Mechanical Ventilation with Heat Recovery (MVHR)
  • Pre-fabricated timber frame in twin wall construction with Superglass 032 full fill and Beltermo wood fiber externally
  • Isoquick insulated raft reducing thermal bridging and providing thermal mass
  • Triple glazing
  • Solar PV tiles to south elevation with solar hot water heating, Tesla Powerwall and car charger
  • Green roofs to single-storey elements

Key Features

High Insulation Values and Glazing

High insulation values (Max U-value 0.15 W/m2K) – mostly 0.11 W/m2K. Also with triple glazed windows (U-values of max 0.8 W/m2K)

Thermal Bridging and Airtightness

Reduction of thermal bridging (including below slab insulation & wood fibre insulation to roof and walls, with added benefit of increased thermal mass). Furthermore, airtightness levels with less than 0.6 air changes.

Solar PV tiles and Battery Storage

440 PV tiles at 15W each to south elevations with 13.5kW battery for energy use after sunset & storing green nighttime energy from the grid in winter.

Eco- Wood burning stove

Eco-ready wood burning stove for wood available on site.

Orientation

Solar gain through generous south facing windows and patio doors.

Hot Water Cylinder

Hot water via Heatrae Sadia mega-flow-eco-solar-PV-ready Hot Water Cylinder.

Other Features

  • Rainwater harvesting for vegetable garden via generous water butts
  • Growing vegetables
  • Planting fruit trees

Cost

The total cost of the build was £450,000 plus another £50,000 for hard and soft landscaping.

Yearly energy costs of the house are zero; with £300 spent on electricity in winter that are balanced by feed-in tariffs and export payments in summer. Charging the electric car becomes a bonus.

Appraisal & Next Steps

Overall the family are very pleased with the development both spatially, in terms of performance and regarding sustainability.

The next action for the property is to finish the refurbishment of the garage and finalise the soft landscaping.

Contacts & Links

Architect link with link to Grand Designs Magazine article and supplier links:

https://www.pad-design.com/treetops