Industrial-to-Residential: The hidden value in industrial properties

A practical guide to planning, architectural and design-led approaches to industrial-to-resi conversion projects

Loft-style living has been in vogue for many years, with some major industrial-to-resi developments currently underway in London. Later this year, however, a new Permitted Development Right promises to open up many more light industrial spaces as prime residential conversion prospects…

Here, architect Mauro Gonzales provides a practical briefing on the planning, construction and design issues and opportunities which may be presented by industrial-to-resi conversion projects.

Planning Approach

On 11th March, 2016, the Government made a number of Amendments to the Town and Country Planning (General Permitted Development) (England) Order 2015. One of the most significant is the new permitted development right to allow conversions from light industrial (Class B1c) to residential (Class C3).

This new right will come into force on 1st October 2017 and it will be a temporary law, expiring in October 2020.

Light industrial buildings are those that are used to produce or manufacture consumer goods such as footwear, household goods, electronic equipment, clothing, shoes or food, or any other goods which can be produced in any residential area without detriment to the amenity of that area, such as would be caused by noise, vibration, smell, fumes, smoke, soot, ash, dust or grit. So it is common to find light industrial properties located near or within residential zones. Some of these neighbourhoods, especially in London, are in the process of gentrification, which will make this type of conversion worth considering in the next few years.

There will be some exceptions and conditions:

  • Prior approval will be required. Key points for planners to consider will be: the impact of transport, the risk of contamination and flooding, and the sustainability of providing industrial property for that area.
  • Permission will be restricted to buildings with a maximum gross floor area of 500 square metres. For larger areas, it might be worth exploring the possibility of making a full planning application and considering developing more than one residential unit.
  • If the site is occupied under an agricultural tenancy, the landlord and the tenant have to agree in writing that the site is no longer required for agricultural purposes.
  • Permission will not be given If the site forms all or part of a site of special scientific interest, a safety hazard area or a military explosives storage area or If building is a listed building or is within the curtilage of a listed building and the site is, or contains, a scheduled monument.
  • The work must be completed within three years of the date of the prior approval.

It should also be noted that, until 1st October 2017, local authorities will apply Article 4 Directions to protect space for light industry in areas where it is needed.

Architectural & Technical Approach

It should be remembered that in many cases these are buildings which were built using technology and standards of construction which were different from those of today, and that, more importantly, they were built for a different use and purpose. It is therefore worth checking:

  • The envelope

Acoustic and thermal insulation and damp: In general, the whole envelope should be upgraded to comply with Building Regulations Document L1 B (conservation of fuel and power in existing dwellings) and to provide an efficient shelter which conforms to current standards of comfort and energy-saving requirements.

Walls: Standards have become quite strict in terms of thermal insulation following the UK´s Climate Change Act, which established a plan and a commitment to reduce carbon emissions substantially. It is advisable to budget for insulated internal finishes on walls which separate the internal habitable space from the exterior, and also to allow space for these finishes, which will result in an increased wall thickness.

Roofs: To comply with the standards mentioned above it is highly likely that the roof will have to be upgraded as well. In industrial buildings, the existing roof was designed for a different purpose, and if it is not properly protected against damp, it will be easier and more cost-effective to replace the entire roof.

Openings & Windows: Whereas, when converting office buildings to residential ones, it is usual to find openings distributed in quite a regular way and peripherally round the building, industrial buildings might feature rather irregular patterns and sizes, and sometimes even a lack of existing openings or an abundance of them grouped in one façade, a situation which is far from ideal when we intend to convert them into residential units, and which causes a limitation internally on possible layouts.

It should also be noted that large glazed openings facing north might not be desirable because they would be too exposed to north cold streams while do not gain any solar radiation, resulting in a lack of this natural source of heat. Document L1 B of the Building Regulations (conservation of fuel and power in existing dwellings) should also be taken into account.

Carrying out any modifications to the external envelope of an existing building is costly and could become a planning issue.

  • The Structure

Steel structures in general will allow more internal flexibility than a concrete or a load-bearing wall structure. Internally-located load-bearing walls could become an important issue and restrict the design and therefore the potential to achieve a satisfactory layout. Moreover, removing these or to re-arranging them can result in important additional costs.

Bear in mind that old structures, especially those made of timber, should always be surveyed to assess their existing condition, since they are subject to several pathologies and in certain cases do not age well, especially if they have been completely or partially exposed to damp.

Ceiling heights and internal space: Industrial spaces, whether  large or small, have a wide range of floor heights, depending on the purpose for which they were created. The minimum head room for any residential space is 2.3 metres for at least 75% of the Gross Internal Area, according to the National Housing Standards.

  • Drainage and waste disposal

It is most probable that new toilets and bathrooms will be needed, so the number and the location of existing waste vent pipes is something essential to look at, also the proposed design has to comply with Building Regulations Document H (Drainage and Waste Disposal).

At this stage, check where waste pipes are located and how they are connected to the public sewer. This will reveal the feasibility of having additional bathrooms in the property and therefore the type and number of potential residential units.

  • Planning Policies

It is advisable to check the property’s deeds and the relevant council planning policies with special reference to Listed Buildings, Conservation Areas and Article 4 Directions, to be confident that our building is not affected by any of these.

It is also worth investing some time to check the archive of planning applications made in the last five years (the archive is public and accessible). Pay particular attention to rejected applications and the reason why these were not approved. This will give you an insight into the way in which the local planning authority is implementing the current policies.

Designer Approach

This interesting trend started as a necessity for artists in New York back in the 1950s, as a way to afford large and open-plan spaces that could be used as a studio and simultaneously as a home. Location was important, as the artists wanted to live and work near to large groups of other artists with similar interests and cultural needs.

Nowadays this type of space has become a luxury and a well established design and living trend, much appreciated in big cities such as London or New York.

The main asset  that  an industrial building possesses is a distinct character that could be described as genuinely raw and honest

The main asset  that  an industrial building possesses is a distinct character that could be described as genuinely raw and honest. With this unique attribute also comes a great challenge, which is to maintain the property´s core industrial character and link it with what we aim to create in that space, and as result end up with a mixture of the old and the new.

By combining elements, attributes, materials and finishes that have bold, raw, hard and un-fancy characters with those that are softer and smoother, we achieve a result based on opposites, and it is precisely this which creates something so unique and attractive.

You will find, below, some easy and simple design and architectural tips to follow to achieve good results when converting from industrial to residential use.

  • Existing finishes & structure

Ideally we want to retain part of the existing structure and finishes of the building. The new elements will then act as a “frame” (in visual terms) for the old features. In this way we will enhance the former character of the building. The contrast between well finished and smooth surfaces and the existing raw, untreated and naked materials brings a beautiful and interesting result.

You will find a few constraints when trying to retain and show naked raw materials, all of which relate to Building Regulations:

Document L1 B (conservation of fuel and power in existing dwellings) and Document E (resistance to the passage of sound): External Walls might need additional insulation to comply with Building Regulations. This is installed generally in the internal part of the wall, so it would not allow us to see the wall´s original material. Insulation can also be installed on the outer part of the wall and a special rendering can then be applied on top of  it, but in most cases this will change the building’s appearance and become a planning issue.

Floors will have to be resistant to the impact of sound (when separating residential units) and partitions will need to be resistant to the passage of sound; an assessment will need to be made in order to check whether the existing and proposed elements comply with these requirements.

Document B Volume 1 (Fire Safety): Leaving an exposed structure is always an interesting option, especially for steel and concrete structures, but one should be aware that these might have to be treated to comply with Building Regulations Document B  (Fire Safety) (sufficient stability of the building under fire load and internal fire spread). Minimum periods of fire resistance for structural elements will need to be checked.

  • Glazing & Windows

Something commonly found in industrial buildings is either big openings or solid façades with no openings at all.  The first scenario is generally welcomed; we might budget for double-glazed windows and frames coated with aluminum polyester powder. We recommend using colour RAL 7016, otherwise known as Anthracite Grey. On the other hand, in the second scenario, we will either propose opening new windows, which could become a structural and planning issue, or seeking natural light through rooflights and double heights.

  • Spacial continuity & open plan

When envisaging  “Loft & Industrial style”  the first adjectives that come to mind are “open”, “flexible” and “large”; these are usually desirable attributes.

Owing to the large size of windows or a lack of them, and to open the possibility of exposing (being able to see)  a pitch roof structure, we might consider installing large rooflights and arranging double heights. This would result in amuch richer, lighter and more continuous space.  And opening viewing angles and  expanding internal views would make the spacelook wider.

To achieve a flexible open plan we recommend the use of a folding or operable wall system when feasible. These have become quite popular and technically advanced in the last few years, and they provide the full flexibility which nowadays is needed more than ever.

  • Furniture, plants and lamps

In contrast with the raw and naked appearance of the industrial style, we need the benefits of elements that provide warmth and coziness. Furniture can play a key role here. We strongly recommend budgeting for this and purchasing good quality pieces,which will be a good investment that will pay back over time.

Furniture: Soft, gentle and rounded qualities are preferable to hard, rough and angled pieces, in order to reach a good balance between industrial and residential.  If we have managed to retain exposed brick or concrete, we might lean towards lighter colours in order to capture and reflect light and to contrast with the walls. Shelves with books make the space more human, and can be used as partitions to separate spaces while keeping the plan open and flexible at the same time.

Rugs: Regardless of floor finishes, and whether they are of wood, tile or polished concrete, rugs really help and have an important impact in differentiating spaces, especially those that are intended to be for sitting in from those which are intended to connect with others (for passing through).

Plants: In the same way as all the above, and for the same reasons, plants have a powerful impact in humanising the surroundings and bringing life to the space. Note that in the UK, owing to a lack of natural light, especially in winter, we might want to choose certain species which, in addition to their beauty and attractiveness, do not need direct sunlight. Examples are: Dracaena, Parlour Palm, Umbrella Papyrus, Snake Plant, Creeping Fig, and Philodendron.

Lamps act as “milestones for the eye”, rather like punctuation marks, so it is worth investing in good quality items

Lamps and lighting: When designing uncommon spaces such as conversions from industrial to residential, we recommend avoiding ambient lighting, which would result in non-differentiated spaces and could give the impression of an art gallery, storage space orhospital. Instead, what we need to look for is focused illumination, which will help us to differentiate between the various spaces and uses. Moreover, lamps act as “milestones for the eye”, rather like punctuation marks, so it is worth investing in good quality items. A mixture of the modern and the traditional is also desirable.

In a scenario with high ceilings or double heights, pendant lights are an interesting option, because they enhance the way we perceive the space, making it appear more vertical and hence higher.

This is a simplified guide that does not aim to cover all construction matters, or act as a conclusive source of legal information, but the cases presented above cover most of the situations that you could face. Always consult a professional.

Mauro Gonzales is Principal at Gonzalez Architects; he specialises in residential architecture, including refurbishment, extensions, conversions, and new-build houses in conservation areas, listed buildings, and metropolitan open land protected areas.