National Trust Café, London

The National Trust expands the already green credentials of Morden Hall Park converting the café to renewable energy.

Case study summary

The Nation Trust approached Worcester Renewable Energy to convert its café at Morden Hall Park in Wimbledon, London to renewable energy to complement the 50 acre’s of green deer park surrounding  it.

A difficult project in terms of access and public safety, the installation was carried out with minimum disruption to both customers and café trading, which involved having to crane all plant and machinery over the River Wandle.

As well as providing all the heating and hot water for the building, Worcester Renewable Energy also designed the system to use the extract heat from the kitchen to pre-charge the ground loops making the system even more energy efficient.

Mrs Colbeck said “We are now a truly green site. Not only can our customers enjoy a green oasis of nature and tranquillity within a busy city, they can now also eat and drink in a building heated by renewable energy, sympathetic to its surroundings.”

Customer testimonial

Worcester Renewable Energy were extremely professional from start to finish and managed to deliver the project without the café having to close, something which was extremely important to us and our customers.
Mrs Colbeck, Estate Manager.

Health & Safety

The Trust’s brief was that the Café was to remain open to its customers throughout the installation.

Prior to the agreed commencement date of the installation, and arrival of the Worcester Renewable Energy installation team, risk assessments and methods statements were completed and signed off by the Trust to ensure the safety of everyone on site.

Arrival on site

Upon arrival to site by the Worcester Renewable Energy installation team, a working area was cordoned off in accordance with the risk and method statements preventing the public from entering but still allowing them access to the café

Plant & machinery

The only access to the café is via a pedestrian foot bridge. This meant that all plant and machinery had to be craned over the river from the adjacent carpark.


A geological survey had been obtained during the design stage of the project to establish the thermal conductivity of the bedrock in the area designated for the boreholes. This enabled the  the number and depth of the boreholes to be correctly calculated ensuring that the incoming brine temperature is always above zero degrees.


Three boreholes were drilled, each inserted with a 40mm ground loop before being backfilled with thermal grout.

Manifold pit

A 1m deep manifold pit was excavated to connect the borehole ground loops to the header pipework serving the ground source heat pump.


Once the boreholes had been drilled, and ground loops inserted, interconnecting trenches were then excavated to bring the ground loop pipework back to the manifold chamber.

Water table

Due to the site being adjacent to a river the water table was extremely heigh meaning that ground loop pipework required weighting down in position before backfilling.

Manifold chamber

Each of the ground loops from the boreholes was connected to the header pipework serving the heat pump in the plant room. This reduced the amount of ground loop pipework entering the plant room where space was restricted.

Plant room

The plant room now contains the ground source heat pump and hot water cylinder which provides all the heating and hot water requirement of the café.