The National Trust HQ

Limetec Hydraulic Lime Mortar and the National Trust – Going Green Together

The National Trust protects and opens to the public more than 300 historic houses and gardens, along with 49 industrial monuments and mills. As a charity, completely independent of government, it relies for income on membership fees, donations and legacies, and revenue raised from commercial operations to keep running.

Therefore, the National Trust was looking to get the best value for money when it commissioned architects Feilden Clegg Bradley to design its new central offices. Constructed in Brunel’s 19th Century rail yard in Swindon, the building also had to offer the most sustainable solution possible within a tight budget that would also match the surrounding, industrial period architecture.

The finished building would have to synergistically combine the future with the traditional, offering a contemporary interpretation of industrial design. In keeping with the green ethos, the client also wanted to eliminate the need for cement and make the structure recyclable.

Limetecs hydraulic lime mortar proved to be the perfect eco friendly product to help Feilden Clegg Bradley meet this brief. Allowing masonry to be recycled when the building comes to the end of its life, and re-absorbing some of the CO2 given off during the firing process when it sets, hydraulic lime mortar offered the ideal characteristics to create a sustainable masonry building.

The Brief

Situated in Brunel’s 19th Century rail yard in Swindon, the National Trust’s new offices were created to offer the most sustainable building possible within the budget. This meant careful consideration of all materials specified.

In addition, the design of the building had to reflect the new building’s location in the Brunel rail yard and offer a functional and practical layout to enable the maximum use of natural daylight and ventilation to reduce energy consumption.

The Solution

Trapezoidal in shape, the exterior of the National Trust’s new central offices, with the exception of the south facing glass façade, is clad in blue engineering bricks and features Limetec’s Limetec® hydraulic lime mortar – a modern day replica of traditional lime mortar.

As well as meeting the client brief by eliminating the need for cement and offering recyclable qualities, lime mortar offers a number of other advantageous properties. With the dexterity to accommodate slight movements in the building caused by settlement or thermal shock without cracking, it reduces the need for expansion joints. It also remains workable for up to 24 hours, has a long-proven performance, offers enhanced aesthetics over similar products and is breathable. As part of a sustainable building design, these properties can help to create a major reduction in a building’s carbon footprint.

To create a comfortable interior environment, Feilden Clegg Bradley also ingeniously used the exterior brickwork as a method of providing solar shading and preventing heat gain within the building. By creating a series of brick fins, which gently protrude alongside the recessed glazed sections, they stop direct sun from hitting the glass and heating the building, while ensuring maximum natural light enters the office space.

An eco-friendly solution with Limetec Lime Mortar

The National Trust’s new central office is an inspirational example of what can be achieved in large scale, new building projects, using sustainable materials.

Limetec has created a solution that enables mortar to be created in bulk on site. Using an innovative silo mixing station, which can store up to 35 tonnes of dry material, ready mixed mortar ßcan be produced at the simple touch of a button. This not only guarantees mix proportions and supply but also eliminates wastage, again reinforcing it as a highly environmentally friendly product.