Is Your Building Hiding a Hotel?

Of course, not every building will work. There are a few fundamentals to check in the early stages: Does it have enough windows? Are the boundary conditions and party walls workable? Are floor-to-floor heights sufficient? These are the sorts of physical criteria that need considered to establish basic viability.

If those basics are in place – or can be resolved – the next step is to work out the scale of development and how many bedrooms and facilities your building might realistically accommodate.

Hotels are generally made up of four main components:

1. Bedrooms

2. Circulation, walls, and service voids
3. Front of House (FOH) — receptions, bars, restaurants, event spaces etc
4. Back of House (BOH) — kitchens, staff rooms, plant, laundry etc

Taken together these make up the gross internal floor area (GIA). The percentage area of each will vary according to location, target market, building constraints and operational model. This guide gives you a clear way to think about these variables – so you can start to shape the type and size of hotel your building could support.

Before we do that, we first need to understand what adaptive reuse is and why it’s a great fit for hotel development.

Adaptive reuse is the process of repurposing existing buildings for new uses. It is a powerful strategy in hotel development offering not just sustainability benefits, but also allowing for character-filled buildings in great locations, often at a lower cost than new builds. However, the transformation of a former bank, townhouse or office into a successful hotel often involves negotiating constraints and making the most of its spatial potential.

To help make sense of this, we analysed ten hotel development projects in Dublin – studying bedroom types and sizes, floorplate layouts and the relationship between front-of-house and back-of-house space. We then compared these findings with our own live and recent work at Galgorm Castle, The Old Inn Crawfordsburn and the Townhouse Hotel Belfast, where we’re actively transforming heritage buildings into high-quality hotel accommodation.

The following five steps draw directly on this research supported by real plans, figures and typical ratios – to help building owners, developers and operators assess the viability of their own sites.

Hotels come in all sorts of shapes and sizes, particularly when it comes to repurposing existing buildings. In the Dublin developments we looked at hotels ranged in size from 480m2 and 24 bedrooms to 22,000m2 with 400 bedrooms. The first step is to establish the gross internal floor area of your existing building — the total area of all floors measured from the inside face of the external walls, excluding voids such as atria or double-height spaces. Don’t worry about potential extensions or infills at this stage as we can consider that later with our Hotel Feasibility Calculator.

Your intended market will set the tone for room sizes, finishes and amenity levels. In our own projects and research, we’ve seen bedroom sizes range from tiny city-break crash-pads to generous country-house suites.

For example:
– 14m² – Budget to Boutique (The Mayson)
– 14–20m² – Boutique to mid-range (The Leinster)
– 20–25m² -Mid-to high-end (The Gresham)
– Up to 50m² – Luxury (Galgorm Castle)

Examples of hotel bedroom floor plans

Smaller rooms suit city-centre sites where location is king. Mid-range rooms work well for balanced boutique offerings. Larger suites tend to be more suited to rural or luxury heritage properties, where guests may be spending more time in their rooms.

It is worth noting however that small rooms can still feel very luxurious and deliver great guest experiences if design and finishes are of the highest quality, such as at the Mayson.

The percentage of floor space for bedrooms in your building will depend upon your operational model – a city centre hotel where all the amenities such as bars, restaurants etc are provided off-site will clearly have a higher percentage of bedroom floor area than a hotel with its own food, beverage or spa offering. In our Dublin developments research the net bedroom accommodation area ranged between 29 – 57% of GIA, with an average of 44%.

The usable bedroom space (net area) on a typical bedroom floorplate is never the same as the space it takes up in the building (gross area). You need to account for walls, circulation and structure. This is also true for floors which have front of house and back of house functions.

For a bedroom floorplate the net bedroom area can typically range anywhere between 60–75% of the gross area – meaning a 20m² room could occupy around 25–30m² in gross terms. The actual figure will depend on:

– The depth and shape of the floorplate (eg. a long thin floorplate with a single row of bedrooms to one side of a corridor will be less efficient than a deeper plan with 2 rows of bedrooms, one either side of a common corridor).

– Heritage constraints (eg. where thick masonary walls and unusual shapes can be less efficient but add quirkiness and unique character).

– Positioning of cores and services (eg. centrally located is typically more efficient).

– Whether it’s new build or adaptive reuse (eg. new build can be purpose designed from the outset, making for more efficient floorplates, whereas adaptive reuse may be less efficient but more than make up for this in character and guest experience).

Based on our research the area required for circulation, cores and walls (CCW) ranges between 16-40% and across the 10 Dublin hotel developments the average was 24% of the GIA.

Galgorm Castle

-73% net to gross (a relatively good ratio as the thick internal walls are compensated by minimal corridor area and large rooms).

-Rectangular shaped floorplan with large bedroom suites and minimal corridors, maximising the net area for the suites. 

Leinster Hotel

-69% net to gross.

-Square plan with two public lifts, a service lift and two stair cores servicing bedroom floors and the restaurant roof terrace.

Mayson Hotel

-66% net to gross.

-Two lifts, a service lift and two stair cores servicing the bedroom floors and the top floor restaurant and roof terrace.

James Place St

-72% net to gross.

-Largest plan and most efficient with internal corridor and rooms either side.

The size and style of your Front of House (FOH) and Back of House (BOH) areas are shaped by your service model. Hotels with full restaurants, bars, spas and gyms need a lot more FOH space than a compact city aparthotel with self-check-in and no in-house dining.

From our Dublin hotel study net areas ranged between:

– FOH: 4-27% of Gross Internal Area with an average of 16%
– BOH: 4–24% of Gross Internal Area with an average of 13%

BOH requirements can also be influenced by site layout — a plot with an external yard for deliveries, waste and plant will need less internal space than one without. FOH can be influenced by external spaces such as beer gardens and terraces which can provide attractive and valuable hospitality spaces.

Once you know your building’s gross area and have a vision for the type of hotel you want, you can start to assess the potential. To help you with this we’ve developed a simple Hotel Feasibility Calculator spreadsheet that allows you to input the areas and the ratios of bedrooms, circulation, front of house and back of house to give you an idea of the type of hotel and number of hotel bedrooms your building could accommodate.

We’ve also set this up so you can not only explore the development potential of the existing building but also the potential for any rooftop or ground-up extensions. Rear, rooftop or courtyard extensions can dramatically improve viability — adding bedrooms, rooftop bars or creating space for other guest facilities. These opportunities of course come with planning, structural and fire considerations, so professional advice is essential.

📩 Get your copy here.

This is a quick way to test scenarios before committing to a full feasibility study, and a good stepping stone to our more in-depth appraisal service.

Some buildings are perfect hotel candidates on paper, but you only really know when you’ve looked closely at the numbers. By understanding the relationship between bedrooms, FOH, BOH and circulation (and how these shift depending on your market) you can make informed, confident decisions.

At Rejen Architects, we combine design creativity with commercial know-how to help you see the potential in your building and turn it into a thriving hospitality destination.

If you’d like to chat about a project of your own please feel free to get in touch here and for more general enquiries get in touch here. We look forward to hearing from you.

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For more content on adaptive reuse, check out the following Rejen Insights articles:

• “Old Buildings, Stranded Assets & The Workplace Revolution”

• “Is Office to Residential Right for Belfast?”.