New Forest EnerPHit achieves certification

No stranger to Passivhaus self-builds, PHT member Ruth Butler Architects demonstrates you need not sacrifice your much-loved home for modern levels of comfort with EnerPHit.

New Forest EnerPHit Certified © Ruth Butler Architects

PHT Members Ruth Butler Architects and Cundall retrofit this New Forest 2-storey detached house to certified EnerPHit standard demonstrating to their clients' delight that you do not need to sacrifice your location to achieve maximum comfort.

Set just 500m from a beautiful stretch of Hampshire coastline offering scenic walks, location is of great importance to the client. Along with aspirations of achieving high indoor air quality and internal comfort, giving a new lease of life to a 1930s family home with a deep green retrofit upgrade was an ideal solution. Originally constructed with brick-cavity and a tiled roof, the renovated home now achieves high levels of energy-efficiency and comfort thanks to its certified EnerPHit credentials.

New Forest EnerPHit

Externally, insulated render encases the house with raised flooring to incorporate insulation underfoot, alongside triple glazed windows and doors specified by PHT Patron member Green Building Store. The carefully considered large windows offer excellent levels of natural daylight, creating strong connections to the outdoor garden and pond, without huge sacrifices to the energy performance.

New Forest EnerPHit

With these key upgrades in place, the original heating system could be removed, and now only a single radiator is required to heat the entire house. By utilising the south-facing orientation of the building, PV panels provide solar energy and hot water.

Internally, the dwelling has been redesigned with contemporary features and an open plan living layout, providing a fresh and welcoming interior to complement the transformation of the family home.

Key Stats

Completion Date: 2019

Certification Date: April 2020

TFA: 144.4m²

Number of Occupants: 4

Construction: Masonry

The retrofit was more challenging then we, naively, thought. Ruth was always positive and was the reason we did not give up. The result has been well worth the effort. Our home is now using only a third of the energy and is much more comfortable, in all weathers. It is a pleasure to live in, the redesigned layout gives us more light and a better connection with the garden.

The Client

Construction

Wall

Externally insulated brick cavity
U-value: 0.267 W/(m²K)

Floor

Suspended timber floor
U-value: 0.166 W/(m²K)

Roof

Insulation over ceiling joists - traditional pitched roof
U-value: 0.089 W/(m²K)

Predicted Energy Performance

Airtightness (≤1.0ACH@50pascals)	1.0 ACH@50pascals
Thermal Energy Demand (≤25kWh/m².yr)	20 kWh/m².yr
Thermal Energy Load (≤10W/m²)	13 W/m²
Primary E Demand (≤120kWh/m².yr + heat load factor)	138 kWh/m².yr