From the sound of it, Ben Balcombe is about to buy a house built like many others in New England in the 1980s: 2×6 walls (presumably insulated with fiberglass batt insulation), double-pane windows, baseboard hydronic heat linked to an oil-fired boiler, and vinyl siding. The house is in southern New Hampshire in Climate Zone 5.

Balcombe plans to renovate the house in phases. He’d launch a kitchen and bath remodel “as soon as we get the keys,” with other upgrades to follow.

His list includes the installation of some new windows and a new slider to replace an existing French door opening onto a three-season sunroom. He also plans on adding a wood stove on the first floor, with the stovepipe exiting the house through a side wall, and replacing an aging electric water heater with a heat-pump water heater.

Because the boiler is only two years old and runs at an efficiency of 86%, Balcombe has no plans to replace it.

For now, the most important question he faces is how to upgrade the insulation in exterior walls.

“Would it be worth taking down the drywall on the exterior walls where I’m remodeling to replace the insulation, or would I be better served looking to apply a layer of rigid foam to the exterior at some point in the future?” Balcombe asks in a Q&A post at Green Building Advisor.

What strategy would make the most sense for Balcombe? That’s the starting point for this Q&A Spotlight.

Don’t rip out the walls quite yet

Before jumping into something as drastic as a gut-remodel, Dana Dorsett advises, it would make sense to do some sleuthing first.

“It’s worth at least some [infrared] imaging of the walls during blower door pressurization/depressurization before committing to rip out…