38B-073 227 South St energy memo
July 31, 2018
To: Louis Hasbrouck, Building Commissioner, City of Northampton
From: Matt Turcotte, Power House Energy Consulting
RE: 227 South Street Redevelopment, Northampton
Louie,
Thank you for taking the time to discuss the redevelopment of 227 South Street and
applicable special permit energy efficiency requirements.
Currently, the building has one existing residential unit, and the owner plans to add 7
additional units to the property. Two of the new units will be on the first floor of the
existing original building, and the remaining 5 proposed units will be new construction.
As you know, the HERS rating system is much better suited to model new construction
than renovation projects. In this case the proposed redevelopment is complicated by the
large existing upper floor apartment in the original building, which the owner plans to
renovate only minimally (existing tenants will be kept in place with minimum
disruption through construction).
As a result, we propose that the original 1884 building be treated separately – via a
prescriptive approach – from the new construction portion of the project. The building’s
2nd and 3rd floors comprise one large existing 1,892 sq. ft. apartment, and the first floor
will be divided into two apartments of 851 sq. ft. and 828 sq. ft. We propose that the
owner improve the energy efficiency of the original building through prescriptive
measures, as follows:
• In the 2nd/3rd floor apartment, which will be minimally renovated, upgrade the
existing older boiler and hot water heater with a 95% efficient combi-unit, replace
single-paned windows with Energy Star windows, and install Energy Star exterior
doors. Maintain the existing blown-in cellulose wall insulation by installing
blocking in the cavities that are exposed below during the gut renovation of the 1st
floor.
• On the 1st floor, which will undergo a comprehensive renovation, all relevant
energy components will be upgraded to meet the 2015 IECC prescriptive code
except where there are already existing double-paned windows. All exterior wall
cavities will be insulated with spray foam to R21, all replacement or new windows
will be Energy Star, and all exterior doors will be upgraded to Energy Star
certified doors. A 95% efficient combi-boiler will also be installed for heating and
hot water.
• The owner proposes to reuse 4 existing 2013 Daikin Mini-Split Heat Pump AC
Units, installing one in each of the first floor apartments, and one on each floor of
the 2nd/3rd floor apartment.
In addition, we propose that the new construction portion of the project (5 units) meet
the special permit requirements of a HERS rating of 47 using the following
specifications:
• R-10 foamboard insulation under the slab and at the slab perimeter
• R-30 closed cell spray foam insulation in the exterior wall cavities
• R-60 blown-in cellulose insulation in the attic
• Energy Star certified windows and doors
• High performance HVAC system, including ductless mini-split heating and
cooling and heat pump water heaters
• LED lighting and some Energy Star certified appliances (refrigerator, dishwasher,
clothes washer & dryer)
• We are also exploring the possibility of photovoltaic panels to generate some of
the electricity for these units
We appreciate your feedback on this proposed strategy at your earliest convenience.
Thank you.