Hilton Design Criteria and the DTBH Hotel Design Process: Afyon

When this unique hotel project arrived on our desk, the structural shell was almost complete and the transition to fit-out was fast approaching. Yet this is precisely one of the most demanding scenarios for a chain-hotel design. The approach of fit-out means a compressed concept phase and imminent deadlines for material decisions. What made things truly difficult, however, was not time but the sharp guest-satisfaction and global safety standards on which the international hotel brand never compromises. On a reinforced-concrete mass whose structural work was already finished, trying to adapt these high international standards to the existing building carried the risk of enormous demolition and breaking work.

Hotel projects are usually dominated by an unavoidable investor psychology: just six months after the investment decision is formally made, they want the first room sold to guests. But as a team (HTIDS) that has managed global chain-hotel design processes in the field for years, the reality is this: we have almost never seen a hotel of that scale open its doors to guests in under two years.

At certain intervals (usually every two years) the Hilton group publishes a design-directives book covering all of its sub-brands. For each brand this book has three main variations within itself:

1. New Build: Projects still on paper, where construction has not begun.
2. Existing Shell: Buildings whose construction is complete but whose interior fit-out is not yet done. (Afyon DTBH fell exactly into this category.)
3. Finished Building (Conversion): A ten-year-old hotel changing brands, or a building with another function being converted into a hotel.

The standards applied and the tolerances differ for each type. For example, Hilton standards require a ballroom door to be drawn 110 cm wide at the project stage. But if the ballroom is already built and demolition is not structurally possible, the investment-assessment teams may accept a 100 cm door as an exception. Decisions like these are the filter for whether a structure "can become the brand or not".

DoubleTree by Hilton Chain Hotel Design Afyonkarahisar Lobby Interior

The biggest and, frankly, the riskiest problem on this intense Afyon project, which had passed the structural stage, was that the existing architectural project unfortunately did not comply with the Turkish Fire Regulation — the foundation of life safety. Because of this shortfall, the two most commercially efficient points of the building, the ones most profitable for tourism revenue, were technically completely unusable:

• Terrace-Floor Bar Area: Completely idle because fire-escape routes and access to the stairs had not been considered.
• Mezzanine Ballroom: The number of fire-escape stairs was not enough to evacuate the crowd density that would form when the ballroom was used at full capacity.

DoubleTree by Hilton Hotel Design Terrace Bar View

The problem in the ballroom ran deeper. We reworked the architectural project, which had divided the area purely by square-metre calculation with no regulatory analysis at all. We composed the ballroom flexibly so that, when needed, it could be turned into three differently sized conference halls with movable partition walls. This gave the operation extra functions it could sell.

To solve the greatest crisis — the fire-stair capacity — we completely revised the WC plans. Without reducing the wet-volume capacity, we created a new safe shaft connecting from the WC area to the lower-floor stair and reached the required evacuation capacity. Thanks to a hidden service corridor we also added, we solved at the root the problem of plates or service trolleys passing in front of guests. Both spaces were brought into compliance with both DTBH standards and the Turkish Fire Regulation, and we shortened the investor's ROI period by two years.

The project the architectural team prepared for the ballroom and its foyer

The regulation-compliant project we developed for the ballroom and foyer area

But the use of marble brought us face to face with Hilton's strict rules. For guest safety, the brand requires hard floors to have internationally certified ceramics with a minimum R11 slip-resistance value. No such standardisation exists for natural marble. With the investor's marble expertise, we applied a special sandblasting process to the quarried natural-stone surfaces, brought their slip-resistance values up to the standard Hilton required, and obtained a certificate from scratch for this special production. Using these certified Afyon marbles at room entrances, in bathrooms and even in the custom décor inside showers gave the project incredible originality.

Afyonkarahisar — Inner Anatolia's gateway to the west — is a dignified geography where volcanic rocks and earth, grey and brown tones hold absolute dominance. In contrast to this centuries-old, solemn steppe landscape outside, we wanted to welcome guests stepping through the hotel's doors with a high-energy, modern and warm atmosphere.

The moment you step into the lobby, the specially worked marble floor wrapping the space, the recessed carpet in the lounge and the wide library detail combine to create a sincere feeling of "home" that embraces the guest. The Alpi-brand timber veneers we used preserve the natural-wood feeling flawlessly, while the vividness of green, purple, yellow and blue spreading homogeneously through the space completely breaks the dullness of the geography outside. This energetic palette continues in an uninterrupted design language from the lobby and bar into the rooms.

On the Afyon project we experienced an incredible level (height) problem at the points where carpet and marble met. There were three different surface dynamics inside the room: standard marble at the entrance, carpet in the middle area, and underfloor-heated marble cladding in front of the window. Had we used ceramic, we could easily have equalised the thicknesses with underlay. But because marble is thicker than ceramic and the underfloor-heating system demands extra volume, to achieve a single finished surface on the room floor we had to pour three different screed heights:

• Entrance (Reference Level): We took the screed under the marble as "level 0". With 2 cm of adhesive + 2 cm of marble thickness, the finished floor reached +4 cm.
• Carpet Area: Moving to the carpet area, taking into account a carpet with 1.2 cm pile height and +0.5 cm underlay thickness, we poured a special screed +1.8 cm (18 mm) above level 0 so the carpet would sit flush with the +4 cm level.
• Underfloor-Heating Area: In the zone with the underfloor-heating pipes in front of the window, since extra space was needed, we poured -2 cm below level 0.

Two days before handover, together with a coordinator from the site team we installed all the artworks and paintings in the hotel ourselves, tape measure in hand, at the top of ladders. Working non-stop for two days, we hung roughly 150 paintings in all the rooms and public areas. Then, together with Hande Tözün, we placed the decorative objects we had chosen on the restaurant, bar and lobby shelves, centimetre by centimetre.

Hanging scheme of the paintings

The paintings hung

Ballroom foyer paintings

Paintings waiting to be hung

We had no time to panic. The whole hotel team, management and site staff all rolled up our sleeves together. By morning the water was drained and the cleaning was done. Without sleeping until dawn, I put back one by one, to the millimetre, all the heavy furniture that had been pulled aside, the decorative objects we had rescued at the last moment from being submerged and whose order was completely disrupted. When İbrahim Bey stepped into the lobby at 05:00, everything looked flawless under that "Golden Hour" light.