Determine why remodeling is necessary or desirable. Energy conservation is a good reason to consider a remodeling of a home from 1960. Pure aesthetics may not be a good reason, given the tremendous expense. Order your remodeling priorities and decide what is most important to you.
Consider changing lifestyles. While families are smaller today than they were in the 1960s, bedrooms are more than sleeping rooms now. Many 1960s homes feature very small bedrooms that people today consider too small. Master bathrooms, with soaker tubs and separate shower stalls, are popular, as are open floor plans. Decide what projects might make your house "more modern" for future owners.
Compare homes in your general neighborhood in terms of valuation, features and square footage. Do not over-remodel and price your home out of sync with your neighborhood. Talk to a real estate professional.
Think about construction logistics. If you will be tearing out walls to upgrade plumbing or ductwork, consider upgrading electrical work as well. After all, once a wall is open, you might as well take advantage of the opportunity. Seek the advice of a contractor.
Address the "bones" of the remodel. Look at the condition of the foundation, the roof and the weight-bearing walls. If these need substantial repair you might as well remodel them completely to gain the use of new materials, more space or further energy savings.
Evaluate the mechanical systems too. The electrical, plumbing, ventilation, heating and cooling systems may need to be updated drastically from 1960s standards, both to comply with current building codes and to satisfy the needs of future buyers. Electrical systems are an excellent example: most 1960s homes do not offer three-prong grounded outlets in rooms and circuits are often protected with old screw-in breakers that are inadequate today.
Focus on "big payoff" remodeling projects. Bathroom and kitchen remodels usually result in the greatest payback at sale time. Finishing or remodeling a basement into a second living room or media room can also bring high returns on initial investment (ROII).
Avoid remodeling projects that do not have a high ROII and are merely window-dressings, literally, such as in-ground pools, extra bedrooms, high-end decks and patios and fancy roof shingles and other exterior trims.
Consider restoring your 1960s home rather than changing it. Restorations are different from remodeling projects as they seek to retain or recapture the original character of the home. Since 1960s homes are vintage now, they may be attractive to '60s fans. There may be value in sticking to the "old" rather than succumbing to the allure of the "new."