Amenity Roof Terrace Renovation: 6 Critical Technical Considerations at the Start of Every Project
Having completed a number of roof terrace renovation projects, here are a few key technical issues that need to be considered and addressed early in the design project in order to confirm the viability of the project and reduce the design and construction risks. These should be tackled in parallel with the programming of your Amenity Space, as the information revealed in these will significantly impact the feasibility, viability, and quality of space possible.
1. Weight | Structural Capacity
How much weight can the structure hold? And where?
There will need to be a structural review and assessment of the existing structure to see what the loading capacity is – this should be done before any concepts are done.
Adding additional structural capacity is often quite costly and does not provide a viable ROI for most projects. The designers will need to work with the existing structural limitations of the roof deck. Often this means that there is limited weight capacity between the structural columns, however there may be areas just above the columns where additional weight could be located. Having a qualified structural engineer on-board early on and working iteratively with the landscape architect is critical to developing a feasible design the first time.
2. Existing Roof Terrace Waterproofing and Insulation
It is critical to understand the existing waterproofing products that are used and how they will integrate with a new landscape roof system – both structural connections and drainage across them. Discussion with the existing waterproofing manufacturer is critical to confirm that all waterproofing materials will continue to be warrantied with the new design implementation.
3. Roof Terrace Drainage
Understanding the current roof drainage system and drain locations, and confirming with the base building / plumbing engineers that there is sufficient capacity in the system for the addition of irrigation water and that they are comfortable with water that is going through soil being discharged into the building roof drains is critical to mitigate against any future issues.
4. Wind Loads
When selecting paving materials, umbrellas, awnings, furnishings, etc. it is critical to know the ‘design to’ wind load for the location that you are in. The wind load will impact both paving material selection as well as anchoring methods that are required for safety. Similarly, for umbrellas, the wind load will impact product selection and required anchoring method to avoid future risks.
5. Fire Codes
Many jurisdictions have codes limiting the percentage of roof covered in flammable materials, this is usually a percentage of the area calculated floor by floor, but in some jurisdictions is calculated across the entire building. This is important in understanding paving material options, and often limits the use of wood decking materials to only a small percentage.
6. Building Maintenance Operations
Most buildings have some sort of Window / Façade Washing Operations that have existing davits or tie off points on the structure that can’t be modified. These points also have a ‘clear’ zone around them in order for them to be utilized effectively. In addition, some window washing operations also include some sort of vehicle or equipment that needs to access these points and will need to get from where it is stored to these locations. All of this will impact the design of the physical elements as well as the structuring of the pavements.
Any other building maintenance operations should also be reviewed and discussed, especially things that require specific access or equipment / vehicles that might impact the terrace.