Long range multistep energy transport has been studied for donor-acceptor systems with excluded volume for donor or acceptor. It has been found that the fluorescence intensity decay of primarily excited donors is slower compared to that of randomly distributed fluorophores with any possible spatial location. This effect is especially strong if acceptors are entrapped in a certain volume inaccessible to donors. The analysis based on Monte-Carlo simulations concerns also other fluorescence characteristics. (C) 2008 Elsevier B.V. All rights reserved.