Survey first: the drawings are rarely the building
In older UAE buildings the as-built drawings, if they exist, seldom match the site after years of tenant changes and repairs. A renovation survey should open ceilings and risers at representative points, trace main pipe and duct routes, record equipment nameplates and condition, measure actual chilled-water and airflow performance, and map electrical loads against board capacity. Asbestos-containing materials in older buildings must be identified before any intrusive work.
The survey also defines what can be reused. Risers, main chilled-water pipework and switchboards may have remaining life while terminal units, controls and pumps need replacing. Testing existing pipework condition, for example with samples or thickness checks, avoids connecting new equipment to corroded mains that will fail under the changed flows.
- Ceiling and riser openings at representative locations
- Equipment nameplates, age and condition records
- Measured airflow, water flow and temperatures
- Electrical load survey against board and supply capacity
- Fire alarm and sprinkler zoning and condition
- Hazardous material identification before demolition
Phasing and shutdown planning
Phasing divides the work into zones that can be isolated without affecting the rest of the building, for example a floor, a wing or a riser at a time. Each phase needs a clear sequence: isolate, protect, strip out, install, test, reconnect and hand back. Interfaces at the boundary between old and new systems, such as tie-ins to chilled-water risers, are where most risk lies and should be designed with isolation valves installed early.
Shutdowns of shared services, chilled water, main power, domestic water and fire systems, should be few, short and scheduled outside occupied hours, typically at night, weekends or academic and holiday breaks. Each shutdown needs a written permit, a rehearsal of the switch-over where possible, an agreed back-out plan and notices to occupants in advance.
Temporary services and keeping occupants comfortable
In UAE summers, loss of cooling is not a nuisance; it can close a building. When central plant or AHUs are replaced, temporary cooling may be needed: rental chillers connected through temporary pipework, spot coolers in critical rooms, or phased switchover so that one plant item always remains in service. Electrical works may need temporary boards or generator supply for critical loads.
Temporary services must be designed and controlled like permanent ones: cable routes protected, pipework pressure-tested, noise and exhaust from generators managed, and fire risks assessed. They also need to be removed cleanly, which should be included in the programme rather than left to the end.
Noise, dust and working hours
Core drilling, chasing, grinding and demolition generate noise and dust that occupants will not tolerate during working hours. Noisy activities are usually restricted to agreed windows. Dust control relies on sealed hoarding, negative-pressure zones with filtered extraction where sensitive areas such as libraries, labs or clinics are adjacent, and protection of existing return-air paths so dust is not drawn into AHUs serving occupied areas.
Smoke detectors in and near the work zone are often affected by dust and hot work, causing false alarms. The usual approach is controlled, permitted isolation of specific detectors by the fire alarm maintenance contractor, with a fire watch in place and detectors restored and tested at the end of each shift.
- Agreed noisy-work windows outside occupied hours
- Sealed hoarding and dust screens with sticky mats
- Negative-pressure extraction near sensitive areas
- Protection or blanking of return-air grilles
- Daily cleaning and waste removal routes away from occupants
Life-safety continuity
The building must remain safe at every stage. Fire alarm coverage, sprinkler protection, smoke control and escape routes should stay operational in occupied areas, and any impairment must be planned, authorised by the building management and, where required, notified to civil defence, with compensating measures such as fire watches and portable extinguishers. Hot-work permits control welding and brazing near combustible finishes.
When fire systems themselves are being upgraded, new panels and devices are typically installed and commissioned in parallel, with the old system kept live until the new one is proven zone by zone. The final cause-and-effect test must cover both renovated and untouched zones because interfaces such as AHU shutdown and lift recall often span the whole building.
Retrofit priorities: what is worth upgrading
Retrofit is a chance to fix chronic problems and improve efficiency. Common upgrades include replacing constant-speed pumps with variable-speed drives, converting three-way valves to two-way pressure-independent valves, adding or upgrading fresh-air units with heat recovery and proper dehumidification, introducing or extending BMS for scheduling and monitoring, LED lighting with controls, and replacing failed or corroded rooftop equipment with units correctly rated for high ambient conditions.
Each upgrade should be checked against the existing system. Variable-flow pumping needs a chiller and control strategy that supports it; added fresh air needs cooling capacity and electrical supply. In Dubai, retrofit projects may also intersect with green building requirements depending on scope, so check the applicable rules early.
Examples from Manolia's renovation work
Manolia's renovation portfolio includes the 3,200 m² library floor renovation at the American University of Sharjah, covering electrical, plumbing, air conditioning and décor, and HVAC and BMS design and build for the AUS main and language buildings, both on a working university campus where academic calendars shape the programme. In Sharjah the group also delivered an A/C renovation for a G+11 twin tower, where cooling had to be replaced in buildings that remained in use.
On projects like these the planning and approvals stages of the delivery process carry more weight than on new builds, because survey findings, shutdown windows and occupant communication determine whether the work can proceed without disrupting the people inside.
Frequently asked questions
Can a central A/C system be replaced while a building stays occupied?
Yes, with careful phasing. Typical strategies are replacing chillers one at a time while the others carry the load, using rental chillers through temporary connections, or scheduling major switch-overs in cooler months or holiday periods. The approach depends on plant redundancy, space for temporary equipment and the building's tolerance for short interruptions.
Do renovation works need civil defence approval?
Works that alter fire and life-safety systems, compartments or escape routes normally need approved drawings and inspection by the civil defence of the emirate, and modifications to electrical supply may need utility approval. The exact requirements depend on scope and location, so the consultant should confirm the approval path before work starts.
How do you prevent false fire alarms during renovation?
Through controlled isolation of detectors in the immediate work area by the authorised fire alarm contractor under a permit, dust containment, and a fire watch while detectors are isolated. Detectors are restored and tested at the end of each shift. Covering detectors without a permit or leaving them isolated overnight is unsafe and should not be allowed.
What is the biggest risk in MEP renovation projects?
Unknown existing conditions. Undocumented services in ceilings, corroded mains, overloaded boards and hidden hazardous materials cause most delays and variations. A thorough intrusive survey before design and pricing reduces this risk far more than any contingency allowance.
How is renovation work scheduled around occupants?
Through an agreed phasing plan, defined noisy-work windows, planned shutdowns at night or weekends, advance notices and a single point of contact for complaints. In schools and universities, works are often concentrated in holidays; in offices and residential buildings, at night and weekends.