Quick question: What was the top-performing asset class of 2012? If you're thinking emerging markets or domestic micro-cap stocks, you'd be wrong. In fact, the best-performing asset class in 2012, by a wide margin, was an area of the market that many investors don't even have exposure to -- global real estate. The Dow Jones Global ex-U.S. REIT index was up a whopping 34.3% last year. And while you shouldn't expect a repeat performance in 2013, you may want to consider adding exposure here if you don't already have it.

A global focus
While institutional investors have been investing in alternative asset classes for quite some time now, Main Street investors have begun jumping on the alternative bandwagon only recently. Commodities, real estate, and other "real return" assets have gradually found their way into more and more retail portfolios. And while real estate investment trusts, or REITs, are a popular choice for folks seeking commercial real estate exposure, most investors tend to focus on domestic investments.

There are a number of solid domestically focused real estate ETFs. The Vanguard REIT Index ETF (VNQ 0.48%), for instance, comes with a super-low 0.10% price tag. Investors who prefer active management or who want to supplement their existing passively invested real estate allocation would do well with a stable, low-risk fund like T. Rowe Price Real Estate (TRREX). But if you want to expand your reach overseas, there are also some great options that focus on that space.

Exchange-traded funds
Exchange-traded funds remain one of the cheapest and easiest ways to get broad exposure to practically any segment of the market, including global real estate. Some of the most inexpensive options in this sector include Vanguard Global ex-U.S. Real Estate ETF (VNQI 0.28%) if you want true international coverage and SPDR Dow Jones Global Real Estate ETF (RWO 0.41%) for global exposure that includes a 54% allocation to the U.S. The Vanguard fund will cost you just 0.35% while the SPDR comes with a 0.50% annual expense ratio. Either is a great choice for low-cost foreign real estate exposure.

Actively managed funds
Investors who want a bit more active guidance when roaming the world for real estate opportunities should consider putting their trust in a money manager with considerable experience in this sector. One great choice is T. Rowe Price Global Real Estate (TRGRX). Although the fund has only been around since 2008, it is headed up by manager David Lee, who has managed the domestically focused T. Rowe Price Real Estate fund since its inception in 1997. Lee follows the same sensible, risk-managed approach in both funds, looking for well-managed real estate companies that are selling at reasonable valuations. U.S. names are featured in the fund, including top holding Simon Property Group (SPG 0.05%), which Lee favors for its portfolio of high-productivity malls and its strong negotiating power with tenants. T. Rowe Price Global Real Estate has a lower risk profile than many similar funds, so this is a good place to start if you're new to the global real estate scene.

If you're looking for a fund that gives its managers a little more leeway and you can live with a few more bumps in the road, Third Avenue Real Estate Value (TVRVX) may be right up your alley. This fund tends to eschew real estate investment trusts in favor of real estate operating companies. The management duo in charge here follows a strict pricing discipline, only buying stocks when they are trading at steep discounts to their estimated value. Both domestic and foreign names live side by side in the portfolio, with U.S. assets accounting for roughly one-quarter of total assets. Outside of the U.S., companies headquartered in Hong Kong, the U.K., Australia, and Canada make up the largest regional allocations.

Management has quite a bit of flexibility built into its mandate, so there's a fair amount of wiggle room within the portfolio. For example, the fund owns home improvement retailer Lowe's (LOW 0.63%), purchased for its strong financial position, durable competitive position, and healthy cash flow. Because of its unique approach, Third Avenue Real Estate Value can move out of step with its peers at times, but over the long run the fund is a fine option for worldwide exposure to the real estate sector.

Don't invest in global real estate funds expecting them to top the charts again in 2013, because they probably won't. But adding a small international real estate allocation to your portfolio should help boost returns over the long run while providing an additional layer of diversification for your existing assets.