Upper Wellingham Barn

Send by emailPDF version
Upper Wellingham Barn
Energy Graph
Emissions Graph


Address: Upper Wellingham Barn, Wellingham Lane, BN8 5SN
Owners: Jane and Mike Johanssen
Type: Barn Conversion
Built: 2006
Beds: 3
Walls: timber frame
Residents: 2 adults, 2 children

Eco Features

Air source heat pump (ASHP)
Double glazing
Solid wall insulation
Underfloor heating
Woodburning stove


In 2012, Jane and Mike bought this barn conversion which had been carried out in 2006. Although the house was well insulated and had underfloorheating pipes, the heat source was a large woodburning stove which was simply not up to the job. This prompted them to install an air source heat pump, which now comfortably heats the house and supplies hot water.

Because the conversion was completed in 2006, it was subject to the quite strict building regulations at that time, which ensured that it was adequately insulated, with solid wall insulation, high performance insulation in the roof and floor, plus double glazing of all windows.

Energy efficiency measures

Heating and hot water

The old woodburning stove, which had been designed to heat the whole house, required constant feeding and never
quite supplied enough heat to meet needs. It was also slow to respond.

This prompted the decision to install a Mitsubishi air source heat pump in March 2013. The installation was carried out by GrEnergy, who were excellent in diagnosing the problems with the old complicated system and specifying and fine tuning the new set up.

Ovesco organised an RHPP grant of £1350 and the balance of the cost was met by a low interest grant from Lewes District Council, organised by Parity Trust, who specialise in green finance.


The walls and roof are insulated with Celotex solid PIR foam inserted between the timbers, probably with an additional layer beneath the roof tiles and weatherboarding, to prevent thermal bridging. The floor was also insulated with 80mm of Celotex above the slab and beneath the underfloor heating. The exact specification of the insulation is not known, but if at any time in the future this were needed it could be retrieved from Building Control’s files for the payment of a small fee.

What is known is that the building elements must have met the 2006 building regulations minimum insulation standards listed below:

Walls: 0.30 W/m2K
Roof: 0.25 W/m2K
Floor: 0.25 W/m2K
Windows: 2.2 W/m2K

The main weakness is the doors, which are only single skin oak planking, making them very draughty. These were probably specified by the conservation department to match the historic appearance of the property, despite not meeting building regulations. However, they could easily be adapted with extra insulation and draughtproofing to perform much better.

Renewables and Low carbon technology

The air source heat pump is powered by electricity, but extracts ‘free’ energy from the surrounding air very efficiently, making it economic to run. The progressive introduction of renewables and the move away from fossil fuels means that carbon emissions from the generation of electricity will gradually reduce, making heat pumps an increasingly low carbon alternative.

Lessons learned/Future improvements

Mike and Jane were advised that the orientation of the roofs was not compatible with solar renewables, but this seems to be incorrect and may be worth revisiting when funds allow. Certainly, solar thermal would work very well with the heat pump and be almost self funding with the current RHPP grant and RHI funding due next year.

It is very hard to heat a whole house effectively with even a large woodburning stove as the main heat source.
Instead, it is better to go for a heat pump or a proper biomass boiler.

The owners hope to draughtproof the doors before winter.


Grant assistance: Ovesco, Lewes: www.ovesco.co.uk
Green finance: Parity Trust: www.paritytrust.org.uk
Heating consultants and ASHP installers: GrEnergy, Worthing. www.solar-sussex.co.uk


Upper Wellingham Barn