Refurbishing attitudes to the office

Recent economic events have undoubtedly dampened enthusiasm and funding for new build schemes, whilst also providing greater impetus to revitalise vacant office space in order to secure future tenants. There is also a longer term trend to upgrade buildings in order to improve their energy efficiency.

Refurbishment can often prove to be the best value option and, when done well, can achieve a quality equivalent to that of a new build. A number of refurbishment options are available, with each offering a range of benefits. But what issues do these raise? And how should we respond to a future where refurbishment rather than rebuild is becoming the norm?

Refurbishment options
Refurbishment costs can vary enormously from ‘light touch’ projects, which involve little more than redecoration at a typical cost of £40 to £60 per ft², right up to a complete strip back to structural frame and further modifications to that original structure, which may cost from £150 to £220 per ft². However, even at these higher levels of refurbishment, where costs are similar to the costs of demolition and new build, refurbishment can still prove to be the best value option.

Before determining whether to go for a refurbishment (and if so, what should remain), a full appraisal should be undertaken to review the costs, value and programme. Increasingly sustainability will also form a part of the appraisal, as this will affect the value too.

While there are some preconceptions that refurbished offices offer poor quality space, if done properly the excellence and value of refurbished property can easily compete with newly built property and can also achieve similarly high sustainability criteria. Refurbishment also has significant advantages in terms of carbon emissions and embedded energy. The most extreme refurbishment, which could involve stripping a building right back to the structural frame, will save the equivalent of 1-2 years worth of emissions at today’s typical rates for a new building.

As buildings become more efficient, this will increase even further, so that for a building with a 50 year design life, keeping the frame could save up to 10% of lifetime emissions, while also reducing demands in terms of transport, resource depletion and waste disposal. Recent research by Sturgis Associates and Davis Langdon suggests that this could result in substantially higher figures for the energy savings.

Refurbishment will also reduce the length of the programme: compared to a new build, the savings can range from 15 to 60% of the overall timescale. Avoiding the demolition and rebuild of a structural frame can save around six months and, if a basement and deep foundations are included, the figure can be much higher. This, coupled with an easier run through the planning process, can make even the most expensive refurbs competitive with new build.

Structural issues
At the lower level of refurbishment, structural work will be fairly simple comprising little more than infilling risers and making or enlarging openings and holes in beams for services. However, a full refurbishment project should undertake a radical review of available options, including considering the removal of columns or walls, relocating or remodelling of cores and also expansion sideways or vertically.

When dealing with a heavy refurbishment, it’s important to look at bold options to achieve the best solutions. Only by running through a wide range of options, testing them and comparing costs and value, can we verify which ones are commercially viable and which are not. In some cases, even if no additional floor area is provided, the value can be increased by creating a less cluttered layout.

Hilson Moran is currently working on the refurbishment of an eleven story office block in the City of London that illustrates these points. The images above, compare the existing layout of a typical floor with the proposed design.

In the existing building, the main core renders one end of the building almost unusable – not only because of its large footprint but also because this leaves only a narrow corridor around it. Although the core provides the lateral stability and supports two main beams running down the spine of the building, it makes economic sense to demolish the core and replace it as shown. The revised layout offers a major increase in useable office space for a very modest increase in gross external area.

Additional space has been gained by a new structural frame at the southern tip to the building. Columns were inserted just inside the building perimeter, allowing the load to be transferred to this frame before the original perimeter columns were demolished. Even with this additional cost, the work was proven to add value to the scheme. When this can be done along a whole facade it can prove to be a very economical alternative to demolition and new build.

Coupled with new cladding and external, glazed lifts to create visual interest, the refurbished building will look and feel like a new development, even though 80% of the structural frame is re-used. Of course, such a major re-working of an existing structure comes at a heavy cost in terms of design effort, but this is more than repaid by the additional value to the client.

Site constraints and land ownership may often limit opportunities to expand sideways. However, if planning consent permits, expanding vertically can also be a good option. Many offices are originally designed with more than enough loading and there are often generous allowances for services and finishes. By using actual loads for services and finishes and reducing live loads closer to the BS requirement, it may be possible to add one or two storeys for every ten floors with no overall increase in foundation load. Where column strengthening is required, this is generally achieved by steel plates or sections both for steel and concrete structures. Carbon fibre wrapping can also prove to be effective, particularly for circular concrete columns.

Going forward, we expect to see major refurbishments becoming more frequent, so facilities managers will need to be highly aware of the challenges and opportunities that refurbishment can provide. As well as the economic advantages that can be gained through faster construction programmes and reduced costs, refurbishment will increasingly be in demand for its impressive sustainable credentials.