On a ground-up build or a major renovation, the mechanical system is on the critical path — and split design-then-bid contracts are where schedules slip and budgets blow up. Com+ Mechanical delivers HVAC design-build as a single accountable source: load modeling, system selection, design coordinated with a licensed Professional Engineer, DOB permit coordination, fabrication, installation, and commissioning under one contract. We work alongside owners, developers, GCs, and architects across the five boroughs and surrounding metro to deliver a system that hits the program, the energy code, and the turnover date.
Systems sized on square-footage rules of thumb instead of a real load calculation short-cycle, control humidity poorly, and waste capital and energy. Engineering the loads to ACCA Manual N or an hourly model right-sizes the plant so the building holds setpoint and runs efficiently — which also matters for Local Law 97 emissions math.
When a separate engineer draws the system and the lowest bidder installs it, gaps in the documents become change orders, and ducts, pipe, conduit, and structure collide in the ceiling. A single design-build team coordinates the model before fabrication, so clashes are resolved on screen, not in the field at premium cost.
Mechanical and NYCECC energy-code filings that start after design is 'done' delay permits and push the turnover date. Coordinating filings with the licensed Professional Engineer inside the design-build scope means the energy-code path, ventilation, and mechanical permits move in parallel with construction documents rather than after them.
Under-designed outdoor air, missing make-up air, or undersized exhaust surface during sign-off and stall the certificate of occupancy. Designing ventilation to ASHRAE 62.1 and the mechanical code from the start — DOAS, ERV, and balanced exhaust — keeps the building compliant and the schedule intact.
Chillers, custom AHUs, switchgear-dependent units, and large RTUs can carry long manufacturing lead times. Locking equipment selection and releasing submittals early in design-build protects the construction schedule instead of discovering a 20-week lead the month before turnover.
A system that is installed but never balanced or commissioned rarely delivers the comfort, airflow, or efficiency it was drawn for, and the owner inherits the callbacks. Carrying TAB and commissioning inside the contract verifies airflow, water flow, controls sequences, and capacity against the basis of design before turnover.
Design-build collapses engineering and construction into one team and one contract, so one team coordinates the design and also installs and commissions the system — eliminating the design-bid-build finger-pointing that drives change orders. Com+ Mechanical provides turnkey commercial HVAC design-build for new construction, core-and-shell, tenant fit-outs, gut renovations, and additions throughout the New York City metro. We start at programming with block heating and cooling loads, run ACCA Manual N (or full hourly energy modeling) against the actual envelope and occupancy, then work with a licensed Professional Engineer on the distribution — central plant, packaged rooftops, variable refrigerant flow (VRF), hydronics, or a hybrid — and coordinate mechanical drawings, sealed by that engineer, and equipment schedules. From there we coordinate DOB/DOB NOW mechanical and energy-code filings with the engineer and carry the project through sheet-metal and pipe fabrication, equipment procurement, rough-in coordinated against structure and other trades, testing and balancing (TAB), controls and building automation system (BAS) integration, and full commissioning. Because one team coordinates the design intent and the installed result, the system that gets turned over to the owner performs to the loads it was drawn for — and is documented for Local Law 97, energy-code, and warranty purposes from day one.
From call to comfort in 4 easy steps
We work with the owner, architect, and GC to define the program, comfort and ventilation criteria, and budget, then run block loads and develop a basis-of-design with a system comparison (central plant vs. packaged vs. VRF vs. hybrid) and a budget-level cost and operating-cost picture.
We complete room-by-room loads, select and schedule equipment, lay out ductwork, piping, and controls, and coordinate mechanical drawings that are sealed by a licensed Professional Engineer. The NYCECC energy-code path is locked and DOB / DOB NOW mechanical and ventilation filings are coordinated in parallel with the engineer of record.
We release submittals and long-lead equipment, fabricate sheet metal and pipe, and install rough-in coordinated through MEP/structural clash detection and trade sequencing. Work is phased to the construction schedule and inspected at each required milestone.
We balance airflow and water flow, integrate and check out the BAS, run functional commissioning of equipment and control sequences against the basis of design, and hand over as-builts, the TAB and Cx reports, O&M manuals, and owner/operator training.
Engineered chilled-water and hot-water plants — chillers, boilers, cooling towers, pumps, and air handlers — for larger office, institutional, healthcare, and mixed-use new construction where central distribution is the efficient choice.
Packaged rooftop and dedicated-outdoor-air designs for retail, commercial, and low- to mid-rise new construction — engineered curbs, structural and rigging coordination, and balanced ventilation built into the documents.
Variable refrigerant flow and air-/water-source heat-pump systems for fit-outs and electrification-driven new construction — zoned comfort with simultaneous heating and cooling and no on-site combustion.
We don't hand a drawing set to a separate installer and walk away. The same firm that coordinates the loads and equipment selection with a licensed Professional Engineer, who seals the documents, also fabricates, installs, and commissions the system — so design intent and installed reality stay aligned.
We coordinate design and DOB / DOB NOW filings, prepared and filed by licensed Professional Engineers, for the realities of New York City buildings — mechanical and ventilation filings, NYCECC energy code, structural and rigging constraints, and occupied-building phasing on renovations and fit-outs..
We coordinate design with a licensed Professional Engineer to the energy code and Local Law 97 emissions thresholds from the basis of design — right-sized, high-efficiency, and electrification-ready systems — rather than building first and discovering a compliance gap later.
From a single fit-out to repeatable mechanical packages across a developer's portfolio, we standardize equipment, controls, and documentation so each project turns over consistently..
No fees. No surprises. Just honest service.
A programming review, block load study, and basis-of-design with a system comparison and budget-level pricing to validate scope, approach, and code path before full engineering.
Turnkey design coordination through commissioning: construction documents sealed by a licensed Professional Engineer, DOB filing coordination, procurement, fabrication, installation, TAB, and commissioning under one contract.
A scheduled maintenance and service agreement on the newly built system to protect the warranty, hold commissioned performance, and keep the building running after turnover.
All design-build pricing is scoped after a programming and feasibility review, because system type, building loads, structural and rigging conditions, code path, and schedule drive the real engineering and construction cost. Pricing is presented as a written, fixed-scope proposal (or a guaranteed-price design-build agreement) before construction begins..
Business+ plans start at $499/year — includes 2 rtu tune-ups, 15% off all services, and priority scheduling.
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Commercial HVAC service for buildings across the five boroughs and nearby counties
Get answers to common questions about our services
In design-bid-build, an owner hires an engineer to produce drawings, then bids those drawings to a separate installing contractor — and any gaps between the two become change orders. In design-build, one firm owns both the design coordination and the construction under a single contract. Com+ Mechanical coordinates the loads and equipment selection with a licensed Professional Engineer, who prepares and files with the DOB, and we fabricate, install, and commission the system, so there's one accountable party for both the coordinated design intent and the installed result. That typically means fewer change orders, tighter coordination, and a faster schedule because design and construction phases overlap.
As early as programming or schematic design. The biggest cost and schedule savings in design-build come from engaging during concept — when block loads, system selection, shaft and roof space, electrical service, and long-lead equipment can still be influenced. Bringing us in early as a design-assist partner lets us budget realistically, value-engineer while changes are still cheap, and lock long-lead equipment before it lands on the critical path. We can also join a project already in design development and take it through documents, filing, and construction.
We coordinate the mechanical design and the DOB / DOB NOW filing process inside the design-build scope, working with licensed Professional Engineers who prepare, seal and file the drawings and the NYCECC energy-code compliance documents. Coordinating early keeps permits from stalling the schedule..
We build compliance in from the basis of design, with a licensed Professional Engineer, rather than retrofitting it later. That means right-sizing equipment to a real load calculation instead of rules of thumb, selecting high-efficiency and electrification-ready systems (heat-pump, VRF, high-IEER plant) where they fit the program, designing economizers and DOAS/ERV for ventilation efficiency, and modeling the result against the NYCECC and the building's Local Law 97 emissions intensity limits. Designing it correctly up front avoids an expensive compliance retrofit after the building is occupied.
Yes. We deliver design-build for single projects and for developers and owners building or renovating across a portfolio in the New York City metro, standardizing equipment, controls, and documentation so each building turns over consistently. After turnover, we provide 24/7 response and maintenance agreements across the five boroughs, Nassau, Westchester, northern NJ, and Stamford to protect the commissioned system..
Yes — commissioning is part of the scope, not an add-on. At turnover you receive a system that has been tested, balanced, and functionally commissioned against the basis of design: verified airflow and water flow, checked-out BAS sequences, and confirmed equipment capacity. The handover package includes as-built drawings, the test-and-balance (TAB) report, the commissioning (Cx) report, O&M manuals, equipment warranties, and operator training so your facilities team can run the building from day one.
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Whether you're at programming on a ground-up build or scoping the mechanical package for a gut renovation or fit-out, Com+ Mechanical delivers the load coordination, drawings coordinated with a licensed Professional Engineer, DOB filing coordination, the installation, and the commissioning under one accountable design-build contract. Get a system designed to your program, your energy-code and Local Law 97 obligations, and your turnover date — with one team responsible from concept to commissioning.
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