Our team over at 3d Architects were involved in a local development this year, during which they were faced with various interesting challenges relating to the architecture.

Ken Wallace, Associate Director at 3d Architects, discusses these challenges and his  approach to them below. We hope the case study might help you in the future when faced with any similar architecture, planning, or site development challenges.

To start, this project required extensive negotiations with various departments of the local authorities – the issues faced included the following:

  • Planning Permissions
  • Conservation
  • Archaeology
  • Highways
  • Natural Resources

First of all, here’s a little background on the project:

Pottergate is a medieval street in within the Norwich city walls to the north-west of the market and lies within the central conservation area. There had previously been planning permissions on the site, but this had expired and a new policy relating to the use of renewable energy prevented a simple extension of the old consent.

Planning Permissions – the challenges

The new owners of the site and the local authority officers were keen to improve on the previous planning permissions for the site, and instructed 3d Architects to take this forward.

However we were immediately presented with constraints by the Conservation Officer, the County Archaeologist, the Highways Engineer and the Planning Officer! The planners were quite clear that due to the tight urban grain, the only acceptable site layout would be a pair of parallel blocks, one fronting the street and the other set back behind an internal courtyard.

The Conservation Issue

The site context includes many Georgian and Victorian buildings, set on the back of the pavement and generally three storeys high.  There are also listed buildings on both sides and opposite.

Image courtesy of Norfolk Library Service – www.picture.norfolk.gov.uk

This archive photograph from around 100 years ago shows the site frontage behind the two nearest carriages. The old dwellings were destroyed during the Second World War and the site was not re-developed until the 1960’s when a printing works was built. An alley way through the frontage gave access to a Baptist chapel; this had an associated Sunday school building but also a cemetery.

Our Architectural Proposal

Our task was to generate a frontage compatible with the rhythm and strata of the adjoining buildings but not one that is a straight copy of the old townhouses.  Working very closely with the local authorities the final solution saw the front block set on the back of the pavement, and conceived as a pair of townhouses with an adjoining building that incorporates a modest arched entrance to the courtyard.

The whole block is three storeys high with the principal rooms arranged at the front. There is a strong vertical emphasis to the proportions, with a repeating pattern of windows and doors that echoes the rhythm of the Nineteenth Century neighbours. The materials for the walls and roof are sympathetic to the historic nature of the area, primarily red stock brick and clay pantiles.

Introducing the arched entrance allowed an increase in usable floor area whilst improving the continuity of the street frontage (which historically had only narrow breaks in it). The scale of the site access point in the previous approval was felt to be out of character with the old street.

The rear block is of a different design but related through the language of the materials. The ground slopes away to the north so the rear building is set about 1.0m lower and is designed as two and a half storeys high thus lowering the eaves. The roof is also largely hipped to reduce the extent of over-shadowing on the neighbouring properties.

The scheme includes a range of sizes of apartments from 41 to 86 sq metres gross internal floor area. Some of the units also have the facility for “Working at Home”.

The Archaeology Issue

As a result of its location within the old city there is the possibility of various layers of archaeological material on the site. However, previous excavations had indicated that the construction of cellars in Victorian times had removed quite a lot of the earlier deposits.

There is still a significant issue over the human remains in the old cemetery, compounded by the presence of a crypt, below the floor slab in the location of the former chapel, containing further burials.

Dealing with a potentially archaeological site – our response

We negotiated with the Ministry Of Justice to get clearance for the proposed foundations and arranged the site layout (e.g. the location of the courtyard garden and the parking spaces), to minimise the disturbance to the ground in the sensitive areas. We are co-ordinating further archaeological excavation work with the County Archaeologist so that all historic material uncovered during construction can be recorded for the local archive.

We worked with a structural engineer to devise a piling scheme that had the minimum of impact on the ground, (bearing in mind that the ground conditions are not particularly favourable – a chalk layer is relatively near the surface).

The Highways Issue

The city council would have preferred this to be a car-free development, however as a city-centre development, cars were recognised to be a necessary inclusion.

The Highways Issue – A Compromise

We ended up with eight parking spaces for the full development. Each flat has been given a cycle shed. There are also cycle bays for visitors. This is considered a highly sustainable location so the occupiers will benefit from easy access to all the facilities of the city centre.

The re-design of the car parking area allowed for a larger communal garden and a reduced area of roadway, whilst still increasing the number of car spaces on the site. The client was keen to install a gate at the entrance to prevent un-authorised use of the car park; we were able to secure the planners and highways agreement to this.

Dealing with refuse on site is an important issue and we were able to provide a solution that discretely accommodates the shared bins in accessible locations and allows for the current and future range of separation for re-cycling different materials.

Ensuring the Conservation of Natural Resources

The current planning policy on energy requires that at least 10% of the energy consumed by the development has to be provided on-site. Our starting point was to design buildings with very low levels of consumption of natural resources. They are highly insulated and placing the main rooms on the sunny front side makes the most of Solar Gain. Heat recovery ventilation systems are included.

The front, southern roofs slopes are ideal for positioning photo-voltaic panels to recover energy from the sun that is converted to electricity. The calculations demonstrate that this comfortably exceeds the 10% threshold.  This arrangement also takes advantage of the Feed-In Tariff scheme, selling surplus electricity back to the National Grid.

Other renewable technologies were explored but found to be unsuitable for this urban location; wind turbines were ineffective in this city location, air-source heat pumps were too noisy, ground source heat pumps would disturb too much archaeology and deliveries and storage of fuel for biomass boilers was prohibitive. Solar thermal heating would have been viable but was likely to generate surplus energy that could not be harnessed. The development also incorporates low-energy lighting and domestic appliances as well as utilising the latest in low water-consumption bathroom and shower fittings.

Other issues

The site was previously fully occupied by the factory and its car park, but will now have a shared garden in the centre of the scheme, together with some small areas of private garden for some of the ground floor flats. The boundary brick walls will be repaired and strengthened.

The soils on the site contain further risks which are also being addressed. There is Japanese Knotweed present so a considerable quantity of soil will be removed and replaced. There is also the potential for contamination of the ground related to the former printing works so a further investigation is being carried out before work starts on site.

A Summary

Pottergate is a pleasant street close to the heart of Norwich in an area that is currently benefitting from a period of regeneration. This scheme will provide a sympathetic reinstatement of the street scene, respecting the older buildings nearby. It sensitively handles the constraints that arise from being in a historically significant location, enhancing the location from a variety of viewpoints and gives a new lease of life to a site that has been overlooked for some time.

If you’re faced with a similar architectural challenge, share your story with us in the comments section below. 3d Architects are also happy to offer advice and services to help you in negotiations with land owners, local authorities etc.

You can find more information on their website: www.3darchitects.co.uk.

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