Making Historic Windows More Efficient

Windows are an important design feature in many Shaker Heights’ homes, from French Classical to Midcentury Modern.  Unfortunately they are also often inefficient, drafty, and may not operate very well.

            There are many ways to address these issues and you may find a combination of solutions best fits your needs.  This may range from seasonal films to interior or exterior storms or complete replacement.

            Our latest award-winning Shaker Heights project, built in 1931 in the Tudor Revival style, had three different types of windows:  the original steel frame windows (many with leaded glass), replacement windows installed in the 1990s, and glass block windows in parts of the basement.  Most of the windows are nineteen inches wide and forty or more inches tall.  All of the original steel frame windows are single pane while the replacements were designed to have an interior storm window.  The replacements are single “lite” windows, meaning there is one pane of glass — a very different look than the originals with the divided panes and lead details.

            While many homeowners might opt to install replacements, modern windows have large frames made of wood, vinyl, uPVC, or aluminum-cladding. Installing these in the narrow windows would have reduced the glass area by two inches or more – making already narrow windows appear oddly narrow.  These replacements, as is required in Shaker Heights, would need approval by the Architectural Board of Review.

            So the solution was a combination of options.  We restored the steel frame windows and installed interior storm windows and cellular blinds, which had the added benefit of making the house quieter.  Then we had our leaded glass contractor create new inserts that replicated the diamond pattern of the originals for the 1990s replacements, which unified the look of the house.  Finally, the basement glass block windows are being replaced with new uPVC triple pane Passive House-certified windows.

            We decided to use this particular window in the basement for a few reasons.  We wanted low maintenance and the windows are in window wells, so uPVC is durable and much more stable than vinyl frames.  We also chose triple pane windows because the u-value, which is similar to the r-value of insulation, makes them very energy efficient for a relatively small price premium (the u-value is a good way to compare windows).  Finally, we chose windows that are Passive House certified because they are very airtight and part of our air sealing strategy (see phius.org for a list of certified windows).

            Equally important to choosing the right replacement windows is the installation.  While this is a technical detail it is very important:  make sure your installer is using an AAMA-approved method for installation (I prefer method A-1).  This ensures that there is proper flashing around the window to keep water and air out, greatly improving the performance of the windows.  Since you probably also have an older home, also make sure your contractor has passed the EPA’s Lead-Safe certification program to minimize your family’s exposure to lead paint dust.

            There are numerous other strategies that are far less costly than restoring or replacing your windows.  Start by simply using a window film, available at your local hardware store, in the winter months to see if this helps.  Replace typical window shades with cellular blinds and heavy curtains.  And make sure the seal around your windows, both inside and out, is not cracking or missing – caulk is the best value for your home improvement dollar!

            Window replacement is costly and should be undertaken after you have exhausted other options.  There are good resources to help you decide on the best solution, including the Cleveland Restoration Society (which is free to Shaker residents), the Home Repair Resource Center in Cleveland Heights (Shaker residents receive a discount on classes), and architects and sustainability consultants (like Coventry Land!).  Most of all, invest in quality windows for the long-term.  Remember our 85-year old steel windows?  They now perform as well as many replacement windows and will for decades to come.

Shaker Life Spring 2016 Article: Ventilation

            As we transition from winter to spring, our thoughts turn to opening up the house to fresh air. But air sealing and proper ventilation are important year ‘round. We'll cover the basics, some common issues, and methods to make your home more comfortable and efficient.
            Air sealing and ventilation – the movement of air through your home – are intimately connected. Ventilation can be either controlled or “natural.” Natural ventilation is called infiltration. This is the air that comes through a drafty window, under the door, or through a receptacle or light switch on an exterior wall. Unless you are building a super-efficient new house, there will always be gaps and cracks for infiltration.

            While for decades builders thought infiltration was beneficial, numerous studies have demonstrated that the more air-tight a house is the more durable and comfortable it is.
            Why? As air is pushed out of your house by your vent hood, clothes dryer, or bathroom fan, outside air seeps in to replace it. If you have a leaky basement window, that will be one source of this “make-up” air. So if it's winter, you are bringing in very cold and dry air. When it meets the warm and humid air in your basement it could lead to condensation around the windows, on the wall, or inside your wall – a common source of mold. Plus your furnace uses energy to heat it.
            Likewise in the summer you are replacing cooler and less humid air with warm and more humid air. This will again lead to condensation and increased energy use.
            You can address many infiltration issues with air sealing. Many of the most common gaps are accessible: around windows, doors, and such places as where your foundation meets the first floor exterior walls if your basement ceiling is unfinished (the “rim joist.”) In these places you can use high quality sealants, weather stripping, and insulation.

            Insulating the rim joist costs only a few dollars at a home improvement store: a roll of batt insulation (unfaced fiberglass), a can of spray foam, and a piece of rigid insulation (usually pink or green). Using gloves and eye protection, simply cut a piece of the rigid insulation to fit between your joists, seal around it with the spray foam, and then cut a piece of the fiberglass to fit snugly in the space (don’t compress it, that actually lessens the effectiveness), then cut a piece of the rigid insulation to fit between your joists snugly to close off where you just put the insulation. Use the spray foam around the edges to fill the gaps and glue the rigid insulation in place. This easy and inexpensive method is very effective and you can do it in a weekend afternoon.  Alternatively you can have an insulation contractor do this work, including using closed-cell spray foam on your rim joist for an even better seal.

            Bathroom fans are another area that can be easy to overlook but play an important part in the health of your home. Every bathroom (even powder rooms) should have a fan – and that fan MUST exhaust to the outside. Go up to your attic (or have your heating technician do it) and make sure the bathroom fans have a duct that goes either out the roof or out an exterior side wall. If the fan simply vents into your attic, have the heating technician correct this. You are dumping warm moist air into a cold dry (in the winter) environment, which can lead to condensation, mold, and rot.

            The other important role a bath fan can play is to meet the code minimum ventilation requirements. This standard has a minimum ventilation rate (expressed in cubic feet per minute or cfm) based on the number of bedrooms and square feet of the home.  For example, a house that is 2,000 square feet and three bedrooms requires a minimum constant ventilation rate of 120 cfm. A typical bath fan ranges from less than 80 cfm to more than 130 cfm, so this means you should have at least one fan running continuously.  The idea is that contaminants, such as CO2 and the gasses from carpets, glues, and products you bring into your home, should be expelled and replaced with fresh outside air. 

            Of course if you have an older home without any bath fans, you should seriously consider having a heating/air conditioning company install them. However, there is a modern alternative that’s even better: a small box known as an ERV, or Energy Recovery Ventilator. 

            Used for decades in commercial buildings, the growing popularity of the Passive House building standard has brought the ERV to homes. Any house will benefit from an ERV as it brings in controlled ventilation and captures the heat from the air being exhausted.  This makes them energy-efficient while supplying your home with filtered fresh air 24/7.

            While an ERV with dedicated ductwork is the best solution, that’s not always possible in an older home. However, you can add one to your existing forced-air furnace or ducted air conditioning system. If you have a boiler and radiators and no air conditioning, you can add one along with a small duct air conditioning system that most heating/air conditioning companies that service Shaker Heights are experts in installing.

Winter Weather Preparedness

As the temperatures drop, we return to seasonal issues of ice dams, snow, and a furnace that seems to be constantly on.  The "Ask This Old House" crew recently did a great episode addressing many of these issues (see below).

Most homes built in the first half of the 1900s suffer from ice dams, unless a prior owner addressed these issues (which is unlikely...).  There are many great resources that explain why ice dams occur, so we will focus on how to either prevent them or treat them.

Preventing ice dams is the best long-term solution, but of course it is also the most difficult and expensive.  The goal is to prevent heat from escaping through your attic and warming the roof surface, where the snow melts.  It then trickles down to your eave or gutter, there it freezes and creates the ice dam.  So to trap the heat inside your house, you need to air seal and insulate.  Unfortunately this sounds easier than it is.

Air sealing your attic floor generally requires removing all of the existing insulation (hopefully you have some, and ideally a lot).  Then all of the gaps and openings (electric boxes for ceiling lights, bath fans, etc.) are either filled or "boxed in".  This entails building a small box, often out of rigid insulation, to cover the electric box or can light, and then sealing around it.  Just piling on more insulation isn't enough - air sealing is a critical step (for more read this article).  But then pile on lots of insulation.  Blown cellulose is a good option and a layer of about 18 inches will get you up to about R-60.

If you currently have access to the attic and store things there, preventing you from adding insulation, you may want to find a different storage place.  Even just the door or hatch to access your attic is leaking a lot of heat.  You can get highly-insulated attic access doors if this is the case.

If this is too big a project to tackle at this point, budget for it down the road and treat the problem.  This is almost always heat tape, which is essentially an electric cable that warms up to melt a pathway for the water.  They use electricity and must either be manually controlled or be attached to a sensor that can tell if there is both cold temperatures and moisture present (otherwise you're wasting a lot of electricity - potentially $15 or $20 a day if you have 100 feet or more).

While you can buy basic systems at home improvement stores, your best value is to have your roofing contractor install a system for you.  He or she will know the proper placement, how much you need, and will work with a licensed electrician to wire it directly into your home's wiring system.  Ideally heat tape is on its own dedicated electric circuit.  If this isn't possible you can plug in to an exterior outlet, but make sure there are no (or very few) other devices drawing power from that circuit at the same time (especially if you still have knob & tube wiring).  My favorite manufacturer is Pentair's Raychem.

The "This Old House" crew also discuss tuning up your snowblower and furnace.  While it's easy to assume that your furnace will crank out heat all winter long, it is well worth the cost to have an HVAC technician do an annual tune up.  And remember to replace your filters!

Ask TOH | Winter-Weather Special