Stakeholders

Function : Designer

LEAP
Mark Siddall
Architect and Passivhaus Designer

Contracting method

General Contractor

Owner approach of sustainability

As farmers Trevor and Judith Gospel recognise that they are custodians of the land.

The rolling landscape of Northumberland is a jewel in the crown of the North East. Just as a precious stone compliments the band of a ring they wanted their home to compliment an Area of Outstanding Natural Beauty.

They wanted the patina of time to enrich their home and the character of the house to develop over decades. Its purpose being to respond to, enrich and evoke a sense of place.

Yet they did not want a traditional house. Nor did they want a home that was alien to its setting. They wanted a characterful home that is harmonious yet distinctive, memorable, unique and meaningful.

Steel Farm comes from the earth. The sun kissed walls are natural stone drawn from the quarry nearest to the site. The roof is Cumbrian slate. Details beguilingly appear to echo traditional design, yet in practice radically reinterpret the past.

Inside the house daylight washes the interior as the windows are positioned, sized and proportioned to carefully frame views across the land and toward the fields where sheep roam freely beneath dramatic skies.

Architectural description

Steel Farm is located near Hexham in the North Pennine Area of Outstanding Natural Beauty (ANOB). Built using traditional construction technology it is the first Certified Passivhaus in Northumberland.

As organic farmers they owned a plot of land where they dreamt of building a comfortable, low energy home that could accommodate them in their old age and minimise their impact upon the environment. They longed to build their own sustainable low energy home so that family could come and stay. (In the winter of 2011 Trevor and Judith Gospel were renting a small, gloomy bothy. That bitterly cold winter they found that the inside of their fridge was warmer than the living room.)

The remote rural location, limited access to utility mains, and onerous planning restrictions incurred significant costs and strongly influenced design. A number of conditions imposed by the local planning department increased costs and nearly prevented the Gospel’s from building their dream home. The house features a solar thermal system for domestic hot water and a reed bed system for the treatment of foul waste water. AECB Water Standards informed the design also.

Delicate negotiations were undertaken to demonstrate the value that the project had to offer the local and regional economy, and the environment. They also saw the removal of a requirement to provide tabling and two chimneys. Ultimately all of these criteria were fulfilled without compromising the client’s desire to achieve the Passivhaus standards of performance.

Planning permission was received in September 2011. Construction commenced in June 2012 and was completed in February 2013.

Trevor and Judith now live in their spacious new, home. The walls are washed with natural daylight and the windows frame views of the rolling hills (allowing surveillance of the livestock). The lights are rarely used.

If you had to do it again?

Definitely train the site trades before starting on site. We did and risk was reduced significantly.

Building users opinion

Trevor Gospel "The construction of our new home has been a real adventure; challenging at times but, all in all, well worth the wait. Both Mark and Joe have met and exceeded our expectations. We had a limited budget and stuck to it. I don't think that we could have been in safer hands."

Judith Gospel “In our old accommodation, a winter or two ago, 2011 I think, we measured the temperature of the fridge and the living room. At one point it was warmer in the fridge! More than the savings in the energy bills and the reduced environmental impact, we are enjoying the comfort of our new home."

Energy consumption

• Primary energy need : 85,00 kWhpe/m².year
• Primary energy need for standard building : 220,00 kWhpe/m².year

Calculation method : Other

CEEB : 0.0862

Breakdown for energy consumption :

Space Heating Demand 14 kWh/m2.yr
DHW 35 kWh/m2.yr

More information :

The precise amount of electrical energy used by the house can not be determined because the electric meter is used for the whole farm.

Envelope performance

• Envelope U-Value : 0,10 W.m^-2.K^-1
More information :

Wall0.1 W/m2K
Roof0.08 W/m2K
Floor0.11 W/m2K
Windows (uninstalled)0.76
Window g-value0.5


• Building Compactness Coefficient : 3,20

Indicator : EN 13829 - n50 » (en 1/h-1)

• Air Tightness Value : 0,32

Users' control system opinion : A digital programmable room stat is used. Radiators are fitted with thermostatic valves.

In practice the digital programmable room stat has proven to be more complex that was desirable.
As the dwelling is a Passivhaus, and space heating demand is already minimised, controlled can be simplified even further. In future a simple seasonal On-Off switch will be used (On from September, Off from March).

Real final energy consumption

Real final energy consumption/m2 : 24,00 kWhfe/m².year

Real final energy consumption/functional unit : 3 649,00 kWhfe/m².year

Year of the real energy consumption : 2 014

Systems

Heating system :
• Condensing gas boiler
Hot water system :
• Condensing gas boiler
• Solar Thermal
Cooling system :
• No cooling system
Ventilation system :
• Double flow heat exchanger
Renewable systems :
• Solar Thermal
• Renewable energy production : 40,00 %
Solutions enhancing nature free gains :

Solar gains optimised and balanced against overheating risks. Internal gains minimised.

Smart Building

BMS :

Complexity avoided. Simple controls used where possible.

GHG emissions

• GHG in use : 15,70 KgCO₂/m²/year
Methodology used :

PHPP calculations used to estimate energy use and carbon emissions

• Building lifetime : 100,00 year(s)

Water management

Rainwater butts used externally.

AECB Water Efficiency Standards were adopted as the basis for minimising mains water, domestic hot water demand and overheating risks.

Low flow fittings, a compact services plan, a microbore plumbing system was utilised so as to minimise the volume of dead legs (< 1.0 litres), and the storage cylinder was superinsulated (100mm compared to standard 50mm.)

Indoor Air quality

Hygienic ventilation (0.3 - 0.4 air changes per hour).
30 m3.h/person

Health & Comfort

Health & comfort : Measured Performance:

Average temperature over the Year 20.3C

Winter:
oAverage Whole House Internal Temperature 18.5C
oAverage External Temperature 5C

Summer:
oAverage Maximum Internal Temperature 23C, Average Maximum External Temperature 15C,
oAverage Maximum Internal Temperature 24.7C, Average Maximum External Temperature 23C



Calculated indoor CO2 concentration :

Calculated household average <1000ppm

Calculated thermal comfort : 20C during winter. 0% >25C during summer.

Measured thermal comfort : Refer to Health & Comfort above.

Acoustic comfort : Noise levels from MVHR designed to be < 25 dB(A) in habitable rooms and < 35 dB(A) in non-habitable rooms

Product

Paul Novus MVHR (supplied by Green Building Store)
PAUL
Green Building Store

Product category : Génie climatique, électricité / Ventilation, rafraîchissement

mechanical ventilation with heat recovery

Passivhaus Certified

Construction and exploitation costs

• Total cost of the building : 307 350 €

Energy bill

• Forecasted energy bill/year : 367,00 €

Real energy cost/m2 : 2.43

Real energy cost/Dwelling : 367

Urban environment

Rural location. As an opperational farm house the dwelling is accessed by car. Public transport is not available. The site is located near Hexham, Northumberland. North East England.

Land plot area

Land plot area : 1 250,00 m²

Built-up area

Built-up area : 15,00 %

Parking spaces

1 car used

Building Environmental Quality