How to budget for energy efficient replacement windows

Few conflicts can plague homeowners more than disputes over the amount of money to budget and spend for energy efficient improvements. This is especially true if you own an older house with special features like non-standard windows. Knowing exactly how much you can afford to spend can free you to make smart decisions for greening your home.

The National Association of the Remodeling Industry has an online Debt-to-Income, or DTI, ratio calculator that tallies your monthly expenses, gross income and the amount you plan to spend each month paying for improvements. It's a good way to realistically assess your ability to afford what you need and want.

Replacement windows prices and your budget

When it comes to budgeting, window manufacturer Milgard has two governing rules of thumb:

1. If your frame is in poor condition, the extra money required for rebuilding it can seriously inflate your installation costs.
2. The greater the energy efficiency of the window, the more you can expect to pay for extra panes, gas fills and coatings.

Another way to control costs is to budget for a sequential project where you replace your south-facing windows first, and then move on to other parts of the house. You can work out an annual budget to complete replacement windows and other necessary green upgrades.

Installation fees are typically based on the number of windows. Doing your homework on features and pricing is a big part of the budgeting process considering that a replacement window installation can cost between $100 and $600 per unit. That's a huge sweep of prices and options.

The windows themselves could cost as little as $100 or as much as $1,000, depending on style, energy efficiency features and size. A new sill or sash may run as little as $45 installed. Bay and bow windows cost the most, typically, with double-hung windows in the $200-$500 range. Prices go up with special finishes, premium spacers, grilles, glass and hardware. Specialty shapes can up the ante; for example, a Gothic style window from Andersen Windows and Doors could have a base price of more than $1,400.

Of course, replacement windows prices fluctuate on the market, and so do installation costs. Andersen notes that exact prices on its products are determined by dealers. Manufacturers sometimes offer deals, so watching the Web or visiting home improvement stores may help you slenderize the final bill.

Buying your replacement windows

Major window manufacturers have a full price list according to product line. You may choose to buy windows where a certified installer comes as part of the package. Poor installation may actually void a manufacturer's guarantee. Be sure to get at least three bids before making any decisions to move forward.

Remember that you may not need the top-of-the-line replacement window to gain energy efficiency. You can strike a balance of features that really suits your climate and existing house.

Get out your calculators and see what your money can buy.