Sustainable refurbishment: Pinnacle House

Total refurb

19 June 2017

Daniel Henn explains how Pinnacle House in south-west London was sustainably refurbished

Pinnacle House in Wimbledon, south-west London (see figure 1), has been refurbished to provide a total of 3,940 sq. m of high-quality sustainable office space.

The client has a strict policy that all such projects should achieve the highest sustainability credentials, where this is practical and viable, achieving a minimum BREEAM rating of “Very Good” and a rating of C for the energy performance certificate on all refurbishment projects, including Pinnacle House.

The building had to comply with the requirements of the London Borough of Merton’s local plan, namely that all non-domestic developments of more than 500 sq. m are expected to be built to a minimum standard of “Very Good”. Other considerations included sustainable urban drainage design and the preparation of a transport statement.

London Plan Policy 5.2B requires, too, that all major non-domestic developments which result in additional floor space of more than 1,000 sq. m should improve on the requirements of Building Regulations Part L 2010 by 35%. In the case of Pinnacle House, the new-build and existing elements also had to be considered separately, coming under Parts L2A and L2B of the Building Regulations respectively.

pinnacle house

Figure 1: Pinnacle House in Wimbledon, south-west London

The developer is obliged to take all reasonable efforts to improve on Part L levels and, where the full 35% improvement cannot be achieved, a carbon offset levy is applied to the shortfall.

Due to the quality of the proposed scheme, including the high thermal performance of the envelope in respect of insulation and its sustainability credentials, it attracted a high-quality tenant that committed to leasing the whole building at completion under an agreement for lease.

Although the building size, timing, function and quality of the space and location were major factors in the tenant’s decision, so too were the sustainable aspects of the building.

In practice

The inclusion of very clear sustainability requirements in the brief made it easy for the team to ensure that these were integrated into the project. By holding BREEAM workshops at an early stage, all initial credits could be secured, and the team would take active responsibility for ensuring sustainability. It was critical to discuss sustainability with the planning department, including the climate change officer, from the first pre-application planning meeting.

This level of stakeholder engagement proved that the client was committed to sustainability and helped in negotiations to determine the best approach. As a result, CO2 emissions associated with the retained part of the building are lower than would be expected from an office building constructed to the current Building Regulations standard.

The facades of the fifth and sixth floors of the extension have been designed using modern building simulation techniques in order to minimise solar gain and heat losses through passive design measures. Photovoltaic panels have also been integrated on the roof to supply low-carbon electricity to the building, while simultaneously maintaining the area available for the green roof and the aesthetic of the building.

The mechanical and electrical building services had to be designed to meet the highest efficiency standards. Features include:

  • high-efficiency ventilation systems including demand-based controls and heat recovery
  • high-efficiency boilers and cooling systems
  • high-efficiency light fittings with sophisticated controls
  • robust energy metering arrangements.

Energy and thermal modelling ensures energy efficiency is balanced with comfort for occupants, which is an equally important consideration.

A living roof has been retrofitted as part of the refurbishment, primarily for the biodiversity benefits it will offer, including roofscape features suitable for birds and for invertebrates.

It was important for both landlord and tenant that consultants worked hard to design out the waste that is often generated when the tenant’s Cat. B requirements – specific fit-out works – result in the stripping out of the landlord’s completed Cat. A installation, the generic fit-out standard for offices before an occupier makes their mark on a space. With close engagement, we were able to include certain of the tenant’s Cat. B items, while leaving out some of those from Cat. A.

The project had to honour commitments made in the planning conditions, the section 106 agreement and the agreement for lease. The team had to ensure that there was a robust set of employer’s requirements for the contractor to fulfil. Rather than using the contract as a stick to beat them, the client’s team worked closely with them to agree how to overcome any technical challenges and ensure that the project met the criteria of both the contract and third-party agreements.

The project owes its effectiveness to setting out clearly at the start the factors that would indicate sustainable critical success, and to ensuring a clear strategy for engaging with the key stakeholders at the right time in order to achieve the best possible outcomes.

Daniel Henn is a partner at Tuffin Ferraby Taylor

Further information

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