HVAC for New England Buildings — Including the Difficult Ones
MJS Construction’s in-house HVAC division installs, replaces, repairs, and maintains heating and cooling systems across Massachusetts and Southern New Hampshire.
Most HVAC contractors walk into a 1910 colonial with brick walls, no ductwork, plaster ceilings, and knob-and-tube remnants, and give you one of two answers: it can’t be done, or it can be done and here’s what your house will look like afterward.
We’ve spent fourteen years restoring exactly those buildings. Our masonry crew cuts and patches brick. Our carpenters open and close walls without leaving a scar. So when our HVAC division designs a system for an older home, the hard part — getting it in there — is work we already do every day.
What We Install and Service
Ductless Mini-Split Systems
The right answer for most older New England homes with no existing ductwork, for additions, for converted attics and finished basements, and for rooms that have never been comfortable. Heating and cooling from one system, zone by zone, with no ducts to run.
High-Velocity Systems
For historic homes where mini-split heads aren’t acceptable visually. Small-diameter flexible tubing routes through existing wall cavities and chases, delivering central air with minimal disruption to plaster, trim, and period detail.
Furnace & Boiler Replacement
Gas, oil, and propane. Full replacement, upgrade to high -efficiency, and conversions. We handle the venting, the chimney liner work, and the masonry involved — in-house.
Central Air Conditioning
New installs and replacements, including full ducted systems where a home can accept them, and heat pump systems where they make sense for the load and the fuel cost.
Commercial HVAC
Rooftop units, split systems, ventilation, and make-up air for restaurants, retail, offices, and multi-family properties. If we’re already doing your buildout or your envelope restoration, the mechanical work runs on the same schedule.
Service & Maintenance
Diagnostics, repairs, seasonal tune-ups, and maintenance agreements for residential and commercial clients.
Why HVAC From a Restoration Contractor?
- The wall repair is included in the thinking. Running a line set through a brick wall, chasing a duct through a joist bay, opening plaster to reach a chase — for a standalone HVAC company that’s someone else’s problem, and it becomes your problem. For us it’s the same crew, the same contract, the same finish standard.
- One schedule, one contract. If HVAC is part of a larger renovation, restoration, or 203(k) project, it’s not a separate vendor you’re chasing. It’s a division of the contractor already running your job.
- We know old buildings. Load calculations in a house with original single-pane windows and no insulation are not the same as in new construction. We size for the building in front of us.
- Licensed and insured. [INSERT MA license numbers — Construction Supervisor, HIC registration, refrigeration/sheet metal licenses, EPA 608 certification] Fully insured with workers’ compensation on every crew.
Service Area
Frequently Asked Questions
Can you put central air in a house with no ductwork?
Yes — usually with a ductless minisplit system or a high-velocity system. Which one is right depends on the layout, the finish level you want to protect, and your budget. We’ll walk the house and tell you honestly which makes sense.
Do you do HVAC work if I’m not doing a renovation with you?
Yes. The HVAC division takes standalone installation, replacement, repair, and service calls.
Will you have to tear up my walls and ceilings?
Some access is always required. The difference with MJS is that our own carpenters and masons close it back up, so patched plaster, brick, and trim match what was there.
Do you handle commercial HVAC?
Yes — rooftop units, split systems, ventilation, and make-up air for commercial and multi-family buildings.
Do you replace oil boilers and convert to gas?
Yes, including the venting, chimney lining, and masonry work a conversion typically requires.
Get a Free HVAC Consultation
Call (781) 245-0008 or email mselig@mjsconstructioninc.com .