38B-073 Energy Memo to Louie 227 South St v3
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.