Woods Hardwick, Knowlhill development, Milton Keynes

Karl Myhill, consultant at Woods Hardwick and the build constructor Parkway Construction MK explain what factors were implemented in the construction of the final two office buildings they designed as part of the Knowlhill development in Milton Keynes.

According to the Office for National Statistics, the UK population is predicted to grow by 4.3 million from 2012–2022. This trend will be reflected in the increasing workforce as well as buildings to accommodate new offices. Such non-domestic buildings are taking on more requirements than ever before to cater for the for the variety of business needs; companies are looking for a future proof workspace that responds not only to present demands but is also able to accommodate future use and provides a comfortable and energy efficient working environment.

Whether it is lower operational costs, better health or increased productivity, we expect our buildings to do more, with energy efficiency and occupant comfort being the main drivers.

This project will conclude the office park development from an earlier planning approval obtained by Woods Hardwick for the AW James Ltd development, with the smaller of the two buildings, Heron House, due to be completed by November this year and the larger of the two buildings, Bewick House, ready for occupation by May 2015.

Occupant comfort

Occupant comfort plays a key role in productivity. The built environment affects comfort through temperature, indoor air quality, lighting, acoustics, physical space, and humidity. Research shows that the green design attributes of buildings and indoor environments can improve worker productivity and occupant health and wellbeing, resulting in bottom line benefits for businesses.

As reported by the British Council for Offices (BCO), with 90 per cent of typical company expenditure being spent on staff compared to one per cent that is spent on energy and water bills, improving productivity just by one per cent swamps utility costs. This is echoed in the World Green Building Council’s (WGBC) Business Case for Green Building, which shows a change in attitude realising that not only occupant comfort, but also ‘green’ building can help influence productivity through their considered designs and measured performances.

Both office buildings are being constructed to a BREEAM Very Good standard. BREEAM takes in to consideration many different aspects of the construction process, from early client consultation, efficient and sustainable design through to post construction activities of monitoring the building’s performance to ensure that the end users are aware of how the building should be run and function.

Woods Hardwick’s design ensures that each building has great emphasis placed on passive design, with building orientation, passive solar shading, fabric insulation and fabric air tightness being priorities in order to create an a comfortable environment to work from.

Both offices’ occupants will benefit from the generous glazing areas which will provide natural daylight, creating a pleasant working space; at the same time lighting loads are reduced – a significant contributor to the buildings’ energy use. Furthermore, Heron House will also offer the advantage of the dramatic views of the Teardrop Lakes.

Energy efficiency

The Knowlhill development has had extensive value engineer- ing carried out – the roofing system has changed from a composite panel to a built up system which offers the same look and insulation properties for a significant saving. The internal cores in both units have been designed to maximise the net lettable office space but still provides open circulation spaces and toilet areas that are desirable for a high quality office environment. Through this process the client has had the benefit of cost savings for reduced construction costs, along with an increase in rental income.

In both buildings the most efficient variable refrigerant flow (VRF) heat recovery air conditioning systems have been utilised along with heat recovery ventilation units, providing significantly more units of heating/cooling for every unit of energy input into the system.

High efficiency LED light fittings are being used throughout all areas. LED light fittings are extremely efficient, providing a high light output for a relatively small power input. This, coupled with the long life expectancy of the fittings and lamps, will reduce maintenance and replacement costs, and suitable lighting controls (automatic, no user input required) offering a very cost effective solution.

Also installed was a roof mounted photovoltaic array, a renewable low carbon technology providing power that will be utilised by the building with any surplus energy generated returned to the grid.

Low water use fittings are being used throughout the buildings with water flow restrictors used on fittings, and automated systems which can detect leaks (via the combined use of water meters and control panels) and shut off the water when the toilet spaces are not in use through automatic solenoid valves.

A site waste management plan has been produced to ensure recycling is maximised and a significant proportion of site waste (approximately 85 per cent) is diverted from landfill. The landscaping scheme has been developed in line with ecologist’s recommendations to ensure a good mix of native, wildlife attracting species are used in the landscape planting.

The main objective of a building design is to provide occupants with a comfortable working environment in order to increase productivity. Thermal comfort, indoor air quality, acoustic quality and lighting, as well as flexible interior design, are very important to attract and retain talent. The way the building as a whole performs is crucial; not only to comply with current legislation, but also in terms of value, with the demand of more sustainable and high-performance buildings.